CVE-2026-43964 json
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 stat…
published 2026-05-04 6 mo ago modified 2026-08-20 2 mo ago also EUVD-2026-27115
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 43%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Postfix Postfix 3.8.16, 3.9.10, 3.10.9
- Red Hat Red Hat Enterprise Linux 10 2:3.8.5-10.el10_2
- Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 2:3.8.5-8.el10_0.1
- Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support 2:2.10.1-9.el7_9.1
- Red Hat Red Hat Enterprise Linux 8 2:3.5.8-8.el8_10
- Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 2:3.5.8-1.el8_4.1
- Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 2:3.5.8-1.el8_4.1
- Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 2:3.5.8-4.el8_6.1
- Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 2:3.5.8-4.el8_6.1
- Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 2:3.5.8-4.el8_8.1
- Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 2:3.5.8-4.el8_8.1
- Red Hat Red Hat Enterprise Linux 9 2:3.5.25-3.el9_8
- postfix Debian 13 3.10.10-0+deb13u1
- postfix Debian 14 3.11.2-1
debian advisories DEBIAN-CVE-2026-43964
- postfix Ubuntu 22.04 LTS 3.6.4-1ubuntu1.4
- postfix Ubuntu 24.04 LTS 3.8.6-1ubuntu0.1
- postfix Ubuntu 25.10 3.10.2-1ubuntu2.1
- postfix Ubuntu 26.04 LTS 3.10.6-4ubuntu2.1
- postfix Ubuntu Pro 14.04 LTS 2.11.0-1ubuntu1.2+esm4
- postfix Ubuntu Pro 16.04 LTS 3.1.0-3ubuntu0.4+esm4
- postfix Ubuntu Pro 18.04 LTS 3.3.0-1ubuntu0.4+esm4
- postfix Ubuntu Pro 20.04 LTS 3.4.13-0ubuntu1.4+esm1
ubuntu advisories UBUNTU-CVE-2026-43964
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- postfix RHEL 9 2:3.5.25-3.el9_8
- postfix-cdb RHEL 9 2:3.5.25-3.el9_8
- postfix-ldap RHEL 9 2:3.5.25-3.el9_8
- postfix-lmdb RHEL 9 2:3.5.25-3.el9_8
- postfix-pcre RHEL 9 2:3.5.25-3.el9_8
- postfix-mysql RHEL 9 2:3.5.25-3.el9_8
- postfix-pgsql RHEL 9 2:3.5.25-3.el9_8
- postfix-sqlite RHEL 9 2:3.5.25-3.el9_8
red hat advisories RHSA-2026:57174RHSA-2026:51436RHSA-2026:51034RHSA-2026:50963RHSA-2026:50964RHSA-2026:26205
- postfix SLE Module for Server Applications 15 SP7, SLE Module for Basesystem 15 SP7 3.8.4-150600.3.6.1
- postfix-bdb SLE Module for Legacy 15 SP7 3.8.4-150600.3.6.1
- postfix SLES for SAP applications 16.0, SLES 16.0 3.10.2-160000.3.1
- postfix SLES LTSS Extended Security 12 SP5 3.2.10-3.33.1
suse advisories SUSE-SU-2026:2781-1SUSE-SU-2026:2780-1SUSE-SU-2026:22335-1
- postfix openSUSE Leap 16.0 3.10.2-160000.3.1
- postfix-bdb openSUSE Leap 16.0 3.10.2-160000.3.1
- postfix openSUSE Tumbleweed 3.11.2-1.1
opensuse advisories openSUSE-SU-2026:21020-1openSUSE-SU-2026:10707-1
- postfix AlmaLinux 9 2:3.5.25-3.el9_8
- postfix-cdb AlmaLinux 9 2:3.5.25-3.el9_8
- postfix-ldap AlmaLinux 9 2:3.5.25-3.el9_8
- postfix-lmdb AlmaLinux 9 2:3.5.25-3.el9_8
- postfix-pcre AlmaLinux 9 2:3.5.25-3.el9_8
- postfix-mysql AlmaLinux 9 2:3.5.25-3.el9_8
- postfix-pgsql AlmaLinux 9 2:3.5.25-3.el9_8
- postfix-sqlite AlmaLinux 9 2:3.5.25-3.el9_8
almalinux advisories ALSA-2026:26205ALSA-2026:25930ALSA-2026:25932
- postfix Rocky Linux 10 2:3.8.5-10.el10_2
- postfix Rocky Linux 9 2:3.5.25-3.el9_8
- postfix Rocky Linux 8 2:3.5.8-8.el8_10
rocky linux advisories RLSA-2026:25930RLSA-2026:26205RLSA-2026:25932
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-43964 updated cvss 7.5
postfix: buffer over-read via malformed enhanced status code
-
Red Hat Enterprise Linux 6 postfix, postfix-perl-scriptsaffected: workaround, no fix planned “Out of support scope”
-
Red Hat Enterprise Linux AppStream (v. 8) postfix-cdb 3.5.8-8.el8_10, postfix-ldap 3.5.8-8.el8_10, postfix-pcre 3.5.8-8.el8_10, postfix-mysql 3.5.8-8.el8_10, postfix-pgsql 3.5.8-8.el8_10, postfix-sqlite 3.5.8-8.el8_10, +1 morefixed: vendor fix RHSA-2026:25932
-
Red Hat Enterprise Linux AppStream (v. 9) postfix 3.5.25-3.el9_8, postfix-cdb 3.5.25-3.el9_8, postfix-ldap 3.5.25-3.el9_8, postfix-lmdb 3.5.25-3.el9_8, postfix-pcre 3.5.25-3.el9_8, postfix-mysql 3.5.25-3.el9_8, +3 morefixed: vendor fix RHSA-2026:26205
-
Red Hat Enterprise Linux AppStream (v. 10) postfix 3.8.5-10.el10_2, postfix-cdb 3.8.5-10.el10_2, postfix-ldap 3.8.5-10.el10_2, postfix-lmdb 3.8.5-10.el10_2, postfix-pcre 3.8.5-10.el10_2, postfix-mysql 3.8.5-10.el10_2, +3 morefixed: vendor fix RHSA-2026:25930
-
Red Hat Enterprise Linux AppStream EUS (v. 10.0) postfix 3.8.5-8.el10_0.1fixed: vendor fix RHSA-2026:51436
-
Red Hat Enterprise Linux BaseOS (v. 8) postfix 3.5.8-8.el8_10fixed: vendor fix RHSA-2026:25932
-
Red Hat Enterprise Linux BaseOS AUS (v.8.4) postfix 3.5.8-1.el8_4.1fixed: vendor fix RHSA-2026:51034
-
Red Hat Enterprise Linux BaseOS AUS (v.8.6) postfix 3.5.8-4.el8_6.1fixed: vendor fix RHSA-2026:50963
show 6 moreshow fewer
-
Red Hat Enterprise Linux BaseOS E4S (v.8.8) postfix 3.5.8-4.el8_8.1fixed: vendor fix RHSA-2026:50964
-
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) postfix 3.5.8-1.el8_4.1fixed: vendor fix RHSA-2026:51034
-
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) postfix 3.5.8-4.el8_6.1fixed: vendor fix RHSA-2026:50963
-
Red Hat Enterprise Linux BaseOS TUS (v.8.8) postfix 3.5.8-4.el8_8.1fixed: vendor fix RHSA-2026:50964
-
Red Hat Enterprise Linux Server (v. 7 ELS) postfix 2.10.1-9.el7_9.1fixed: vendor fix RHSA-2026:57174
-
Red Hat Enterprise Linux AppStream AUS (v.8.4) postfix-cdb 3.5.8-1.el8_4.1, postfix-ldap 3.5.8-1.el8_4.1, postfix-pcre 3.5.8-1.el8_4.1, postfix-mysql 3.5.8-1.el8_4.1, postfix-pgsql 3.5.8-1.el8_4.1, postfix-sqlite 3.5.8-1.el8_4.1, +1 more Red Hat Enterprise Linux AppStream AUS (v.8.6) postfix-cdb 3.5.8-4.el8_6.1, postfix-ldap 3.5.8-4.el8_6.1, postfix-pcre 3.5.8-4.el8_6.1, postfix-mysql 3.5.8-4.el8_6.1, postfix-pgsql 3.5.8-4.el8_6.1, postfix-sqlite 3.5.8-4.el8_6.1, +1 more Red Hat Enterprise Linux AppStream E4S (v.8.8) postfix-cdb 3.5.8-4.el8_8.1, postfix-ldap 3.5.8-4.el8_8.1, postfix-pcre 3.5.8-4.el8_8.1, postfix-mysql 3.5.8-4.el8_8.1, postfix-pgsql 3.5.8-4.el8_8.1, postfix-sqlite 3.5.8-4.el8_8.1, +1 more Red Hat Enterprise Linux AppStream EUS (v. 10.0) postfix-cdb 3.8.5-8.el10_0.1, postfix-ldap 3.8.5-8.el10_0.1, postfix-lmdb 3.8.5-8.el10_0.1, postfix-pcre 3.8.5-8.el10_0.1, postfix-mysql 3.8.5-8.el10_0.1, postfix-pgsql 3.8.5-8.el10_0.1, +2 more Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) postfix-cdb 3.5.8-1.el8_4.1, postfix-ldap 3.5.8-1.el8_4.1, postfix-pcre 3.5.8-1.el8_4.1, postfix-mysql 3.5.8-1.el8_4.1, postfix-pgsql 3.5.8-1.el8_4.1, postfix-sqlite 3.5.8-1.el8_4.1, +1 more Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) postfix-cdb 3.5.8-4.el8_6.1, postfix-ldap 3.5.8-4.el8_6.1, postfix-pcre 3.5.8-4.el8_6.1, postfix-mysql 3.5.8-4.el8_6.1, postfix-pgsql 3.5.8-4.el8_6.1, postfix-sqlite 3.5.8-4.el8_6.1, +1 morenot affected: vulnerable code not present
+9 more productsfewer
Red Hat Enterprise Linux AppStream TUS (v.8.8) postfix-cdb 3.5.8-4.el8_8.1, postfix-ldap 3.5.8-4.el8_8.1, postfix-pcre 3.5.8-4.el8_8.1, postfix-mysql 3.5.8-4.el8_8.1, postfix-pgsql 3.5.8-4.el8_8.1, postfix-sqlite 3.5.8-4.el8_8.1, +1 more Red Hat Enterprise Linux BaseOS AUS (v.8.4) postfix-debuginfo 3.5.8-1.el8_4.1, postfix-debugsource 3.5.8-1.el8_4.1, postfix-cdb-debuginfo 3.5.8-1.el8_4.1, postfix-ldap-debuginfo 3.5.8-1.el8_4.1, postfix-lmdb-debuginfo 3.5.8-1.el8_4.1, postfix-pcre-debuginfo 3.5.8-1.el8_4.1, +3 more Red Hat Enterprise Linux BaseOS AUS (v.8.6) postfix-debuginfo 3.5.8-4.el8_6.1, postfix-debugsource 3.5.8-4.el8_6.1, postfix-cdb-debuginfo 3.5.8-4.el8_6.1, postfix-ldap-debuginfo 3.5.8-4.el8_6.1, postfix-lmdb-debuginfo 3.5.8-4.el8_6.1, postfix-pcre-debuginfo 3.5.8-4.el8_6.1, +3 more Red Hat Enterprise Linux BaseOS E4S (v.8.8) postfix-debuginfo 3.5.8-4.el8_8.1, postfix-debugsource 3.5.8-4.el8_8.1, postfix-cdb-debuginfo 3.5.8-4.el8_8.1, postfix-ldap-debuginfo 3.5.8-4.el8_8.1, postfix-lmdb-debuginfo 3.5.8-4.el8_8.1, postfix-pcre-debuginfo 3.5.8-4.el8_8.1, +3 more Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) postfix-debuginfo 3.5.8-1.el8_4.1, postfix-debugsource 3.5.8-1.el8_4.1, postfix-cdb-debuginfo 3.5.8-1.el8_4.1, postfix-ldap-debuginfo 3.5.8-1.el8_4.1, postfix-lmdb-debuginfo 3.5.8-1.el8_4.1, postfix-pcre-debuginfo 3.5.8-1.el8_4.1, +3 more Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) postfix-debuginfo 3.5.8-4.el8_6.1, postfix-debugsource 3.5.8-4.el8_6.1, postfix-cdb-debuginfo 3.5.8-4.el8_6.1, postfix-ldap-debuginfo 3.5.8-4.el8_6.1, postfix-lmdb-debuginfo 3.5.8-4.el8_6.1, postfix-pcre-debuginfo 3.5.8-4.el8_6.1, +3 more Red Hat Enterprise Linux BaseOS TUS (v.8.8) postfix-debuginfo 3.5.8-4.el8_8.1, postfix-debugsource 3.5.8-4.el8_8.1, postfix-cdb-debuginfo 3.5.8-4.el8_8.1, postfix-ldap-debuginfo 3.5.8-4.el8_8.1, postfix-lmdb-debuginfo 3.5.8-4.el8_8.1, postfix-pcre-debuginfo 3.5.8-4.el8_8.1, +3 more Red Hat Enterprise Linux Server (v. 7 ELS) postfix-perl-scripts 2.10.1-9.el7_9.1 Red Hat Enterprise Linux Server Optional (v. 7 ELS) postfix-sysvinit 2.10.1-9.el7_9.1
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
| CISA ADP | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
- Postfix Postfix
- Red Hat Red Hat Enterprise Linux 10
- Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
- Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
- Red Hat Red Hat Enterprise Linux 8
- Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
- Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
- Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
- Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
- Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
- Red Hat Red Hat Enterprise Linux 9
- Red Hat Red Hat Enterprise Linux 6
Classification
- Weakness
-
- CWE-193 Off-by-one Error
References
-
access.redhat.com
/errata/RHSA-2026:57174
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:51436
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:25930
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:25932
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:26205
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:51034
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:50963
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:50964
vendor-advisory
-
mail-archive.com
/postfix-announce@postfix.org/msg00110.html
mailing-list, third-party-advisory
-
openwall.com
/lists/oss-security/2026/05/04/30
mailing-list, third-party-advisory
-
access.redhat.com
/security/cve/CVE-2026-43964
vdb-entry
-
bugzilla.redhat.com
/show_bug.cgi?id=2466488
issue-tracking
- security.access.redhat.com /data/csaf/v2/vex/2026/cve-2026-43964.json
Sources
- CVE List CVE-2026-43964
- NVD CVE-2026-43964
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.