- Dovecot-news - dovecot.org

CVE-2025-30189 notification
by Aki Tuomi 29 Oct '25

29 Oct '25

Affected product: Dovecot IMAP Server Internal reference: DOV-7830 Vulnerability type: CWE-1250 (Improper Preservation of Consistency Between Independent Representations of Shared State) Vulnerable version: 2.4.0, 2.4.1 Vulnerable component: auth Report confidence: Confirmed Solution status: Fixed in 2.4.2 Researcher credits: Erik <erik(a)broadlux.com> Vendor notification: 2025-07-25 CVE reference: CVE-2025-30189 CVSS: 7.4 (CVSS3.1:AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N) Vulnerability Details: Using auth caching with oauth2 passdb, passwd passdb or userdb, or passwd userdb, causes the first lookup to be cached for all the lookups. This is because the cache key is "%u" which no longer actually expands to same as "%{user}". Workaround: Disabling auth cache will prevent the issue. Fix Install non-vulnerable version of Dovecot. Patch can be found at https://github.com/dovecot/core/compare/a70ce7d3e2f983979e971414c5892c4e301…

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Dovecot and Pigeonhole v2.4.2 released
by Aki Tuomi 29 Oct '25

29 Oct '25

Hi! We are pleased to release version 2.4.2 of Dovecot and Pigeonhole. Important notice that we are adding new dependency of libpcre2 in this release to implement support for regular expressions in more safe manner. This release adds support for Debian Trixie and Red Hat Enterprise Linux 10, and removes support for Debian Bullseye and Red Hat Enterprise Linux 8. https://dovecot.org/releases/2.4/dovecot-2.4.2.tar.gz https://dovecot.org/releases/2.4/dovecot-2.4.2.tar.gz.sig https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.2.tar.gz https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.2.tar.gz… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot -- Dovecot NEWS * CVE-2025-30189: Passdb oauth2 (not oauth2 mechanism), passdb passwd, passdb bsdauth, and userdb passwd drivers would cause users to be cached with same cache key when auth cache was enabled. * auth: Remove proxy_always field. * config: Change settings history parsing to use python3. * doveadm: Print table formatter - Print empty values as "-". * imapc: Propagate remote error codes properly. * lda: Default mail_home=$HOME environment if not using userdb lookup * lib-dcrypt: Salt for new version 2 keys has been increased to 16 bytes. * lib-dregex: Add libpcre2 based regular expression support to Dovecot, if the library is missing, disable all regular expressions. This adds libpcre2-32 as build dependency. * lib-oauth2: jwt - Allow nbf and iat to point 1 second into future. * lib: Replace libicu with our own unicode library. Removes libicu as build dependency. * login-common: If proxying fails due to remote having invalid SSL cert, don't reconnect. + auth: Add ssl_client_cert_fp and ssl_client_cert_pubkey_fp fields, see https://doc.dovecot.org/latest/core/summaries/settings.html#ssl_peer_certif… for more information. + config: Add support for $SET:filter/path/setting. + config: Improve @group includes to work with overwriting their settings. + doveadm kick: Add support for kicking multiple usernames + doveadm mailbox status: Add support for deleted status item. + imap, imap-client: Add experimental partial IMAP4rev2 support. + imap: Implement support for UTF8=ACCEPT for APPEND + lib-oauth2, oauth2: Add oauth2_token_expire_grace setting. + lmtp: lmtp-client - Support command pipelining. + login-common: Support local/remote blocks better. + master: accept() unix/inet connections before creating child process to handle it. This reduces timeouts when child processes are slow to spawn themselves. - SMTPUTF8 was accepted even when it wasn't enabled. - auth, *-login: Direct logging with -L parameter was not working. - auth: Crash occured when OAUTH token validation failed with oauth2_use_worker_with_mech=yes. - auth: Invalid field handling crashes were fixed. - auth: ldap - Potential crash could happen at deinit. - auth: mech-gssapi - Server sending empty initial response would cause errors. - auth: mech-winbind - GSS-SPNEGO mechanism was erroneously marked as not accepting NUL. - config: Multiple issues with $SET handling has been fixed. - configure: Building without LDAP didn't work. - doveadm: If source user didn't exist, a crash would occur. - imap, pop3, submission, imap-urlauth: USER environment usage was broken when running standalone. - imap-hibernate: Statistics would get truncated on unhibernation. - imap: "SEARCH MIMEPART FILENAME ENDS" command could have accessed memory outside allocated buffer, resulting in a crash. - imapc: Fetching partial headers would cause other cached headers to be cached empty, breaking e.g. imap envelope responses when caching to disk. - imapc: Shared namespace's INBOX mailbox was not always uppercased. - imapc: imapc_features=guid-forced GUID generation was not working correctly. - lda: USER environment was not accepted if -d hasn't been specified. - lib-http: http-url - Significant path percent encoding through parse and create was not preserved. This is mainly important for Dovecot's Lua bindings for lib-http. - lib-settings: Crash would occur when using %variables in SET_FILE type settings. - lib-storage: Attachment flags were attempted to be added for readonly mailboxes with mail_attachment_flags=add-flags. - lib-storage: Root directory for unusable shared namespaces was unnecessarily attempted to be created. - lib: Crash would occur when config was reloaded and logging to syslog. - login-common: Crash might have occured when login proxy was destroyed. - sqlite: The sqlite_journal_mode=wal setting didn't actually do anything. - Many other bugs have been fixed. -- Pigeonhole NEWS * lib-sieve: Use new regular expression library in core. * managesieve: Add default service_extra_groups=$SET:default_internal_group. + lib-sieve: Add support for "extlists" extension. + lib-sieve: regex - Allow unicode comparator. - lib-sieve-tool: sieve-tool - All sieve_script settings were overriden. - lib-sieve: storage: dict: sieve_script_dict filter was missing from settings. - sieve-ldap-storage: Fix compile without LDAP.

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Red Hat Enterprise Linux 8 packages
by Aki Tuomi 08 Sep '25

08 Sep '25

Hi! Due to algorithm limitations, we have signed the RHEL8 packages for 2.4.1 with Dovecot 2.3 signing key. This should make it verifiable on RHEL8. Regards, Aki Tuomi Open-Xchange oy

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Dovecot lifecycle announcement
by Aki Tuomi 12 May '25

12 May '25

We are announcing these Dovecot end-of-life (EOL) decisions: 1. All Dovecot versions before 2.3 are now fully EOL. We will not provide any additional patches, including security issues, for these releases. 2. For Dovecot CE 2.3 we will provide critical security bug fixes. Thus, if you are experiencing a non-security issue with Dovecot, we need you to upgrade into latest 2.4 CE release and reproduce the problem there in order for the team to debug. The Dovecot team will no longer debug non-security related issues for 2.3 releases. If the issue can occur with the latest 2.4 release, please file a bug report and we will take a look! If you are using a 2.3.x version packaged from an Operating System Vendor, please open a bug against them for fixing it. We do not provide patches or bug fixes against these OS Vendor specific releases. Dovecot CE 2.4.x is the current main release, which will continue to receive feature, bug and security patches. We accept bug reports against latest 2.4 version or "main" branch of Dovecot. Packages for Dovecot CE 2.4 can be found at https://repo.dovecot.org. Thank you for using Dovecot! Note: Users with a commercial agreement with Open-Xchange (Dovecot Pro) have a separate extended EOL policy, so this announcement does not apply to them. Regards, Aki Tuomi Open-Xchange oy

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Dovecot v2.4.1 released
by Aki Tuomi 28 Mar '25

28 Mar '25

Hi! We arey happy to release Dovecot v2.4.1! Some IMPORTANT things to notice (still): - We have changed the signing key for 2.4 going forward, releases are signed with EF0882079FD4ED32BF8B23B2A1B09EF84EDC5219, which can be found at https://repo.dovecot.org/DOVECOT-REPO-GPG-2.4 and is signed with the previous key. The old key has been renamed to https://repo.dovecot.org/DOVECOT-REPO-GPG-2.3. - New 2.4 packages **are not** compatible with old 2.3 configuration, please carefully review https://doc.dovecot.org/2.4.1/installation/upgrade/2.3-to-2.4.html before installing the new packages. - We are happy to provide experimental arm64 support in the form of a Docker image. There are now three kinds of images, latest, latest-dev and latest-root. - The latest docker image is now ran rootless, with UID 1000 as vmail. Please take this into consideration when upgrading. The latest-root image still runs as root. Latest 2.3 image can be used with tag 2.3-latest still We won't be sending separate mail about Pigeonhole anymore as we will release one anyways when we release Dovecot, and Pigeonhole versioning has been changed to match Dovecot versioning. Source codes available at - https://www.dovecot.org/releases/2.4/dovecot-2.4.1.tar.gz - https://www.dovecot.org/releases/2.4/dovecot-2.4.1.tar.gz.sig - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.1.tar.gz - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.1.tar.gz… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- Dovecot Core NEWS ----------------- * auth: Change unix_listener/auth-userdb/group = $SET:default_internal_group This change needs dovecot_config_version=2.4.1. * auth: lua - Remove support for single string result. * imap: Unconditionally advertise SPECIAL-USE capability. * lib-dcrypt: Install dcrypt_openssl.so into dovecot modules directory. * lib-master: For glibc, default MALLOC_MMAP_THRESHOLD_=131072. * lib-storage: Change default mail_cache_fields to: hdr.date hdr.subject hdr.from hdr.sender hdr.reply-to hdr.to hdr.cc hdr.bcc hdr.in-reply-to hdr.message-id date.received size.virtual imap.bodystructure mime.parts hdr.references hdr.importance hdr.x-priority hdr.x-open-xchange-share-url pop3.uidl pop3.order. This change needs dovecot_config_version=2.4.1. * lib-var-expand: Use moduledir instead of pkglibdir for crypt. * lmtp: Change the default lmtp_user_concurrency_limit to 10. This change needs dovecot_config_version=2.4.1. * lmtp: Change the default service_restart_request_count to 1. This change needs dovecot_config_version=2.4.1. + auth: Allow configuring passdb/userdb sql to use auth-workers. + config: Add default group @mailbox_defaults = english. + config: Improve "Unknown setting" error with more details and suggestions. + doveconf: Add -U parameter to ignore unknown settings in config file. + fts-flatcurve: Support lock files in VOLATILEDIR. + imap-acl: Add support for the IMAP LIST-MYRIGHTS capability (RFC 8440). + imap-client: Support ANONYMOUS authentication. + imap: Implement support for the REPLACE capability. - auth: ldap - Passdb fields were ignored with passdb_ldap_bind_userdn=yes. - auth: lua - Fix error result handling in lua passdb/userdb. - auth: oauth2 - When building oauth2 failure reply, memory would leak. - config: local_name handling would work wrong with multiple names and wildcards. - fts-flatcurve: A potential crash could occur when searching virtual mailboxes. Fixes: Panic: file fts-search.c: line 87 (level_scores_add_vuids): assertion failed: (array_count(&vuids_arr) == array_count(&br->scores)) - fts-flatcurve: Maybe queries were done wrong. - fts-flatcurve: Non-selectable mailboxes were not ignored when doing optimize/rescan. - fts-flatcurve: Signal 11 crash could happen with fts rescan. - fts: Fix crash caused by event object lifecycle mishandling. - imap-hibernate: Client counters would get reset on unhibernation, affecting imap_logout_format variables. - imap: Crash would occur with Maildir when trying to send INPROGRESS during mailbox syncing. - ldap: Dovecot could not be compiled without LDAP. - lib-dcrypt: Output stream encryption can cause assert crash if attempting to encrypt over 64 GiB of data with GCM. This is still not supported with GCM, but it fails better. - lib-http: HTTP client context memory usage was increasing. - lib-http: Pipeline corruption could happen after 100 Continue response. - lib-settings: Variable expansion initialization could crash with Panic: file settings.c: line 1560 (settings_var_expand_init_add): assertion failed: (I_MAX(num_tables, num_provs) == num_ctx) - lib-smtp: Pipelining initial SASL response after AUTH was broken. - lib-var-expand: If filter failed, memory leak would occur. - lib-var-expand: Older bison versions did not have error symbol for handling causing unexpected behaviour on the parser on error conditions. - quota: Quota calculations had minor bugs causing small errors. Pigeonhole NEWS --------------- - global: Fix settings handling bugs. Especially %variables weren't working in various settings. - ldap: Pigeonhole could not be built without LDAP.

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Dovecot v2.4.0 released
by Aki Tuomi 24 Jan '25

24 Jan '25

Hi all, after a very long wait we are finally happy to release Dovecot v2.4.0! Some IMPORTANT things to notice: - We have changed the signing key for 2.4 going forward, releases are signed with EF0882079FD4ED32BF8B23B2A1B09EF84EDC5219, which can be found at https://repo.dovecot.org/DOVECOT-REPO-GPG-2.4 and is signed with the previous key. The old key has been renamed to https://repo.dovecot.org/DOVECOT-REPO-GPG-2.3. - New 2.4 packages **are not** compatible with old 2.3 configuration, please carefully review https://doc.dovecot.org/2.4.0/installation/upgrade/2.3-to-2.4.html before installing the new packages. - We are happy to provide experimental arm64 support in the form of a Docker image. - Docker images are now ran rootless, with UID 1000 as vmail using built sources. Please take this into consideration when upgrading. Latest 2.3 image can be used with tag 2.3-latest, if you are not ready for this change. We won't be sending separate mail about Pigeonhole anymore as we will release one anyways when we release Dovecot, and Pigeonhole versioning has been changed to match Dovecot versioning. Source codes available at - https://www.dovecot.org/releases/2.4/dovecot-2.4.0.tar.gz - https://www.dovecot.org/releases/2.4/dovecot-2.4.0.tar.gz.sig - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.0.tar.gz - https://pigeonhole.dovecot.org/releases/2.4/dovecot-pigeonhole-2.4.0.tar.gz… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- Dovecot Core NEWS ----------------- * config: dovecot_config_version must be the first non-comment line in configuration file. * config: dovecot_storage_version must be in the configuration file. * config: Many configuration options have changed so old configuration files do not work without rewrite. See https://doc.dovecot.org/main/installation/upgrade/2.3-to-2.4.html * config: New variable expansion syntax has been introduced, see https://doc.dovecot.org/main/core/settings/variables.html * config: Some default settings have changed. * config: plugin {} section has been removed. * *-login: With ssl=required, connections from login_trusted_networks are now also required to be SSL/TLS encrypted. * acl: Use ACL settings instead of Global ACL Directories. * auth-worker: auth_worker_max_count is replaced with service auth-worker { process_limit }. * auth: Weak password schemes are disabled by default, use auth_allow_weak_schemes to enable them. * auth_debug, mail_debug: Use log_debug filter instead. * config: All sections require a name, for example passdb/userdb: passdb static { password=secret } * db2: Remove Berkeley DB support. * dict-memcached: This is removed, use Redis instead. * director: Feature has been removed. See potential replacement at https://github.com/dovecot/tools/blob/main/director.lua * doveadm: USER environment variable is only supported with --no-userdb-lookup. One of -u, -F or -A must be used otherwise. * doveconf: Option -n is now default when running doveconf. * dsync: Use doveadm sync instead, legacy symlink has been removed. * fs-sis: Feature is now deprecated and has been made read-only. It will be removed in future release. * fts-lucene, fts-squat: These have been removed, use fts-flatcurve or fts-solr instead. * imap-login: IMAP compression is now handled in proxies. * imap_quota: SETQUOTA / quota_set has been removed. * imap_zlib: This plugin is no longer needed, it's always enabled. * imapc: All features are enabled by default, imapc_features can be used to explicitly disable features that are not wanted. * lib-storage: mbox driver is now frozen. * mail_compress: XZ and LZMA algorithm support has been removed. * mailbox-alias: Plugin has been removed. * old_stats, auth_stats: These have been removed. * openssl: Minimum supported version of OpenSSL is now 1.1.1. * openssl: Add support for OpenSSL 3.x * quota-dict, quota-dirsize: These have been removed, use quota-count instead. You can use quota_clone to copy quota usage to some database. * replicator: Feature has been removed. Use NFS or some other shared filesystem instead, or run doveadm sync in crontab. * stats: The bytes_in and bytes_out field in several events have been renamed as net_in_bytes and net_out_bytes. * zlib: Renamed to mail_compress plugin. + Experimental SMTPUTF8 and IMAP UTF8=ACCEPT support has been added. Needs --enable-experimental-mail-utf8 configure option and mail_utf8_extensions=yes setting. + Long running mail commands can be aborted with Ctrl-C / doveadm kick. + auth: LDAP driver now supports multi-value attributes. + auth: Add support for SCRAM-SHA-1-PLUS and SCRAM-SHA-256-PLUS. + auth: Add support for TLS channel binding. + auth: Support sending JA3 hash to policy server. + configure: Detect latest Lua version. + *-login: Support for TLS Server Name has been improved to allow pre-login settings. For example capabilities to be changed based on TLS Server Name. + *-login: Support for TLS ALPN has been added, connections with mismatching application are now refused. Missing ALPN is accepted. + fts-flatcurve: New Xapian based FTS plugin has been added. + imap: Support for INPROGRESS untagged messages as per RFC 9585. + lib-lua: Expose Dovecot DNS client. + lib-lua: Expose Dovecot HTTP client. + lib-sasl: Support SCRAM-SHA mechanisms. + lmtp: SNI support has been added which allows settings to be applied based on TLS Server Name. + sqlite: Support WAL mode. + stats: Submetric name size has been increased. + submission: Add submission_add_received_header setting to protect sender identity by suppressing the Received: header. - Many bugs have been fixed. Pigeonhole NEWS --------------- * Change configuration syntax to match new Dovecot configuration syntax. * vacation: Reduce default days to 60 from infinity * vacation: vacation_max_period=0 is now an error. * Version has been changed to match Dovecot version. + Added i;unicode-casecmp comparator. - Lots of bugs have been fixed.

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CVE-2024-23184: Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive
by Aki Tuomi 14 Aug '24

14 Aug '24

Affected product: Dovecot IMAP Server Internal reference: DOV-6464 Vulnerability type: CWE-770 (Allocation of Resources Without Limits or Throttling) Vulnerable version: 2.2, 2.3 Vulnerable component: lib-mail Report confidence: Confirmed Solution status: Fixed in 2.3.21.1 Researcher credits: Vendor internal discovery Vendor notification: 2024-01-30 CVE reference: CVE-2024-23184 CVSS: 5.0 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N) Vulnerability Details: Having a large number of address headers (From, To, Cc, Bcc, etc.) becomes excessively CPU intensive. With 100k header lines CPU usage is already 12 seconds, and in a production environment we observed 500k header lines taking 18 minutes to parse. Since this can be triggered by external actors sending emails to a victim, this is a security issue. The main problem is that each header line's address is added to the end of a linked list. This is done by walking the whole linked list, which becomes more inefficient the more addresses there are. Workaround: One can implement restrictions on address headers on MTA component preceding Dovecot. Fix: Install non-vulnerable version of Dovecot. Patch can be found at https://github.com/dovecot/core/compare/8e4c42d%5E...1481c04.patch

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CVE-2024-23185: Very large headers can cause resource exhaustion when parsing message
by Aki Tuomi 14 Aug '24

14 Aug '24

Affected product: Dovecot IMAP Server Internal reference: DOV-6601 Vulnerability type: CWE-770 (Allocation of Resources Without Limits or Throttling) Vulnerable version: 2.2, 2.3 Vulnerable component: lib-mail Report confidence: Confirmed Solution status: Fixed in 2.3.21.1 Researcher credits: Vendor internal discovery Vendor notification: 2024-01-31 CVE reference: CVE-2024-23185 CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Vulnerability Details: Very large headers can cause resource exhaustion when parsing message. The message-parser normally reads reasonably sized chunks of the message. However, when it feeds them to message-header-parser, it starts building up "full_value" buffer out of the smaller chunks. The full_value buffer has no size limit, so large headers can cause large memory usage. It doesn't matter whether it's a single long header line, or a single header split into multiple lines. This bug exists in all Dovecot versions. Incoming mails typically have some size limits set by MTA, so even largest possible header size may still fit into Dovecot's vsz_limit. So attackers probably can't DoS a victim user this way. A user could APPEND larger mails though, allowing them to DoS themselves (although maybe cause some memory issues for the backend in general). Workaround: One can implement restrictions on headers on MTA component preceding Dovecot. Fix: Install non-vulnerable version of Dovecot. Patch can be found at https://github.com/dovecot/core/compare/f020e13%5E...ce88c33.patch

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Pigeonhole v0.5.21.1 released
by Aki Tuomi 14 Aug '24

14 Aug '24

Hi all, we are releasing new version of Pigeonhole. https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.21.1… https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.21.1… Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- - sieve: When saving to local storage failed after a successful action in sieve (e.g. redirect, vacation), the mail was reported as successfully delivered, although it was lost locally.

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Dovecot v2.3.21.1 released
by Aki Tuomi 14 Aug '24

14 Aug '24

Hi all, we are releasing a CVE patch release 2.3.21.1. https://dovecot.org/releases/2.3/dovecot-2.3.21.1.tar.gz https://dovecot.org/releases/2.3/dovecot-2.3.21.1.tar.gz.sig Binary packages in https://repo.dovecot.org/ Docker images in https://hub.docker.com/r/dovecot/dovecot Kind regards, Aki Tuomi Open-Xchange oy --- - CVE-2024-23184: A large number of address headers in email resulted in excessive CPU usage. - CVE-2024-23185: Abnormally large email headers are now truncated or discarded, with a limit of 10MB on a single header and 50MB for all the headers of all the parts of an email. - oauth2: Dovecot would send client_id and client_secret as POST parameters to introspection server. These need to be optionally in Basic auth instead as required by OIDC specification. - oauth2: JWT key type check was too strict. - oauth2: JWT token audience was not validated against client_id as required by OIDC specification. - oauth2: XOAUTH2 and OAUTHBEARER mechanisms were not giving out protocol specific error message on all errors. This broke OIDC discovery. - oauth2: JWT aud validation was not performed if aud was missing from token, but was configured on Dovecot.

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