CVE-2026-42006
An attacker can cause uncontrolled memory usage with excessive bracing over IMAP. The fix in CVE-2026-27857 was incomplete, only blocking one way of doing this, so there was still another way left
02 Description
An attacker can cause uncontrolled memory usage with excessive bracing over IMAP. The fix in CVE-2026-27857 was incomplete, only blocking one way of doing this, so there was still another way left
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.62% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 49.4% of scored records. A rank, not a probability.
- NVD base score
- 4.3 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- NVD analysis status
- Modified. NVD last modified this record on 2026-10-26.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-05-12 13:28Z5 MO AGO
- Last updated
- 2026-08-03 12:05Z2 MO AGO
- Reserved
- 2026-04-23
- Assigning CNA
- OX
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 4.3)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- Weaknesses
- Data version
- 5.2
- Document digest
- 81bdcc4f17b6f1b993f365798782d7449ff7fdebde9e14507d0398bf3ebfae70
05 Affected products
06 References
- documentation.open-xchange.comhttps://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json
- access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-42006
- bugzilla.redhat.comRHBZ#2476476https://bugzilla.redhat.com/show_bug.cgi?id=2476476
- security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42006.json
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:49513
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:42091
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:41988
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:46532
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:46380
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:46379
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:46381
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:44373
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:44357
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:44355
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:41905
07 Fixed in
AlmaLinux 8
- dovecot Fixed in 1:2.3.16-8.el8_10
- dovecot-devel Fixed in 1:2.3.16-8.el8_10
- dovecot-mysql Fixed in 1:2.3.16-8.el8_10
- dovecot-pgsql Fixed in 1:2.3.16-8.el8_10
- dovecot-pigeonhole Fixed in 1:2.3.16-8.el8_10
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 9
- dovecot Fixed in 1:2.3.16-18.el9_8.1
- dovecot-devel Fixed in 1:2.3.16-18.el9_8.1
- dovecot-mysql Fixed in 1:2.3.16-18.el9_8.1
- dovecot-pgsql Fixed in 1:2.3.16-18.el9_8.1
- dovecot-pigeonhole Fixed in 1:2.3.16-18.el9_8.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 10
- dovecot Fixed in 1:2.3.21-19.el10_2.1
- dovecot-devel Fixed in 1:2.3.21-19.el10_2.1
- dovecot-mysql Fixed in 1:2.3.21-19.el10_2.1
- dovecot-pgsql Fixed in 1:2.3.21-19.el10_2.1
- dovecot-pigeonhole Fixed in 1:2.3.21-19.el10_2.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- dovecot Fixed in 1:2.3.16-8.el8_10
- dovecot-devel Fixed in 1:2.3.16-8.el8_10
- dovecot-mysql Fixed in 1:2.3.16-8.el8_10
- dovecot-pgsql Fixed in 1:2.3.16-8.el8_10
- dovecot-pigeonhole Fixed in 1:2.3.16-8.el8_10
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 9
- dovecot Fixed in 1:2.3.16-18.el9_8.1
- dovecot-devel Fixed in 1:2.3.16-18.el9_8.1
- dovecot-mysql Fixed in 1:2.3.16-18.el9_8.1
- dovecot-pgsql Fixed in 1:2.3.16-18.el9_8.1
- dovecot-pigeonhole Fixed in 1:2.3.16-18.el9_8.1
Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 10
- dovecot Fixed in 1:2.3.21-19.el10_2.1
- dovecot-devel Fixed in 1:2.3.21-19.el10_2.1
- dovecot-mysql Fixed in 1:2.3.21-19.el10_2.1
- dovecot-pgsql Fixed in 1:2.3.21-19.el10_2.1
- dovecot-pigeonhole Fixed in 1:2.3.21-19.el10_2.1
Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- dovecot Fixed in 1:2.3.19.1+dfsg1-2.1+deb12u6
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- dovecot Fixed in 1:2.4.1+dfsg1-6+deb13u6
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- dovecot Fixed in 1:2.4.4+dfsg1-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- dovecot No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- dovecot No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- dovecot No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- dovecot Fixed in 1:2.3.16+dfsg1-3ubuntu2.9
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- dovecot Fixed in 1:2.3.21+dfsg1-2ubuntu6.5
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 25.10
- dovecot Fixed in 1:2.4.1+dfsg1-5ubuntu4.2
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- dovecot Fixed in 1:2.4.2+dfsg1-3ubuntu2.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- dovecot No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.