CVE-2026-43964
Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and process crash via an enhanced status code that lacks text after the third number.
02 Description
Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and process crash via an enhanced status code that lacks text after the third number.
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
- 0.51% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 43.2% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-08-20.
- 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
- 2026-05-04 18:10Z5 MO AGO
- Last updated
- 2026-08-20 12:31Z2 MO AGO
- Reserved
- 2026-05-04
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Low (CVSS 3.7)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
- Weaknesses
- CWE-193Off-by-one ErrorBase
- Data version
- 5.2
- Document digest
- 3781ba89021f571ab8b85bf65c64d5fd9c68b59bff2db4ed42724c0062073922
05 Affected products
06 References
- www.mail-archive.comhttps://www.mail-archive.com/postfix-announce@postfix.org/msg00110.html
- www.openwall.comhttp://www.openwall.com/lists/oss-security/2026/05/04/30
- access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-43964
- bugzilla.redhat.comRHBZ#2466488https://bugzilla.redhat.com/show_bug.cgi?id=2466488
- security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43964.json
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:57174
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:51436
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:25930
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:25932
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:26205
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:51034
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:50963
- access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:50964
07 Fixed in
AlmaLinux 8
- postfix Fixed in 2:3.5.8-8.el8_10
- postfix-cdb Fixed in 2:3.5.8-8.el8_10
- postfix-ldap Fixed in 2:3.5.8-8.el8_10
- postfix-mysql Fixed in 2:3.5.8-8.el8_10
- postfix-pcre Fixed in 2:3.5.8-8.el8_10
- postfix-perl-scripts Fixed in 2:3.5.8-8.el8_10
- postfix-pgsql Fixed in 2:3.5.8-8.el8_10
- postfix-sqlite Fixed in 2:3.5.8-8.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
- postfix Fixed in 2:3.5.25-3.el9_8
- postfix-cdb Fixed in 2:3.5.25-3.el9_8
- postfix-ldap Fixed in 2:3.5.25-3.el9_8
- postfix-lmdb Fixed in 2:3.5.25-3.el9_8
- postfix-mysql Fixed in 2:3.5.25-3.el9_8
- postfix-pcre Fixed in 2:3.5.25-3.el9_8
- postfix-perl-scripts Fixed in 2:3.5.25-3.el9_8
- postfix-pgsql Fixed in 2:3.5.25-3.el9_8
- postfix-sqlite Fixed in 2:3.5.25-3.el9_8
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 10
- postfix Fixed in 2:3.8.5-10.el10_2
- postfix-cdb Fixed in 2:3.8.5-10.el10_2
- postfix-ldap Fixed in 2:3.8.5-10.el10_2
- postfix-lmdb Fixed in 2:3.8.5-10.el10_2
- postfix-mysql Fixed in 2:3.8.5-10.el10_2
- postfix-pcre Fixed in 2:3.8.5-10.el10_2
- postfix-perl-scripts Fixed in 2:3.8.5-10.el10_2
- postfix-pgsql Fixed in 2:3.8.5-10.el10_2
- postfix-sqlite Fixed in 2:3.8.5-10.el10_2
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- postfix Fixed in 2:3.5.8-8.el8_10
- postfix-cdb Fixed in 2:3.5.8-8.el8_10
- postfix-ldap Fixed in 2:3.5.8-8.el8_10
- postfix-mysql Fixed in 2:3.5.8-8.el8_10
- postfix-pcre Fixed in 2:3.5.8-8.el8_10
- postfix-perl-scripts Fixed in 2:3.5.8-8.el8_10
- postfix-pgsql Fixed in 2:3.5.8-8.el8_10
- postfix-sqlite Fixed in 2:3.5.8-8.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
- postfix Fixed in 2:3.5.25-3.el9_8
- postfix-cdb Fixed in 2:3.5.25-3.el9_8
- postfix-ldap Fixed in 2:3.5.25-3.el9_8
- postfix-lmdb Fixed in 2:3.5.25-3.el9_8
- postfix-mysql Fixed in 2:3.5.25-3.el9_8
- postfix-pcre Fixed in 2:3.5.25-3.el9_8
- postfix-perl-scripts Fixed in 2:3.5.25-3.el9_8
- postfix-pgsql Fixed in 2:3.5.25-3.el9_8
- postfix-sqlite Fixed in 2:3.5.25-3.el9_8
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
- postfix Fixed in 2:3.8.5-10.el10_2
- postfix-cdb Fixed in 2:3.8.5-10.el10_2
- postfix-ldap Fixed in 2:3.8.5-10.el10_2
- postfix-lmdb Fixed in 2:3.8.5-10.el10_2
- postfix-mysql Fixed in 2:3.8.5-10.el10_2
- postfix-pcre Fixed in 2:3.8.5-10.el10_2
- postfix-perl-scripts Fixed in 2:3.8.5-10.el10_2
- postfix-pgsql Fixed in 2:3.8.5-10.el10_2
- postfix-sqlite Fixed in 2:3.8.5-10.el10_2
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
- postfix No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- postfix Fixed in 3.10.10-0+deb13u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- postfix Fixed in 3.11.2-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- postfix Fixed in 3.6.4-1ubuntu1.4
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- postfix Fixed in 3.8.6-1ubuntu0.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 25.10
- postfix Fixed in 3.10.2-1ubuntu2.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- postfix Fixed in 3.10.6-4ubuntu2.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- postfix Fixed in 2.11.0-1ubuntu1.2+esm4Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- postfix Fixed in 3.1.0-3ubuntu0.4+esm4Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- postfix Fixed in 3.3.0-1ubuntu0.4+esm4Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- postfix Fixed in 3.4.13-0ubuntu1.4+esm1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
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.