RHSA-2026:51436: Important: postfix security update

Published Aug 6, 2026
·
Updated

Important: postfix security update

Other sources

The postfix packages provide a Mail Transport Agent (MTA), which supports protocols like LDAP, SMTP AUTH (SASL), and TLS.Security Fix(es): postfix: buffer over-read via malformed enhanced status code (CVE-2026-43964) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

— Red Hat

Affected Software

80 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for ARM 64 - 4 years of updates
Red Hat Red Hat Enterprise Linux for x86_64 - 4 years of updates
Red Hat Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Red Hat Enterprise Linux for Power, little endian - 4 years of support
Red Hat Red Hat Enterprise Linux for IBM z Systems - 4 years of updates
Red Hat Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Update Support
redhat/postfix<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-cdb<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-cdb-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-debugsource<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-ldap<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-ldap-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-lmdb<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-lmdb-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-mysql<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-mysql-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pcre<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pcre-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-perl-scripts<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pgsql<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pgsql-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-sqlite<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-sqlite-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-cdb<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-cdb-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-debugsource<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-ldap<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-ldap-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-lmdb<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-lmdb-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-mysql<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-mysql-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pcre<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pcre-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-perl-scripts<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pgsql<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pgsql-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-sqlite<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-sqlite-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-cdb<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-cdb-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-debugsource<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-ldap<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-ldap-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-lmdb<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-lmdb-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-mysql<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-mysql-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pcre<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pcre-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-perl-scripts<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pgsql<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-pgsql-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-sqlite<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix-sqlite-debuginfo<3.8.5-8.el10_0.1
3.8.5-8.el10_0.1
redhat/postfix<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-cdb<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-cdb-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-debugsource<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-ldap<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-ldap-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-lmdb<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-lmdb-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-mysql<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-mysql-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-pcre<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-pcre-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-perl-scripts<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-pgsql<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-pgsql-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-sqlite<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa
redhat/postfix-sqlite-debuginfo<3.8.5-8.el10_0.1.aa
3.8.5-8.el10_0.1.aa

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/postfix to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  2. Upgrade

    Upgrade redhat/postfix-cdb to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  3. Upgrade

    Upgrade redhat/postfix-cdb-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  4. Upgrade

    Upgrade redhat/postfix-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  5. Upgrade

    Upgrade redhat/postfix-debugsource to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  6. Upgrade

    Upgrade redhat/postfix-ldap to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  7. Upgrade

    Upgrade redhat/postfix-ldap-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  8. Upgrade

    Upgrade redhat/postfix-lmdb to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  9. Upgrade

    Upgrade redhat/postfix-lmdb-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  10. Upgrade

    Upgrade redhat/postfix-mysql to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  11. Upgrade

    Upgrade redhat/postfix-mysql-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  12. Upgrade

    Upgrade redhat/postfix-pcre to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  13. Upgrade

    Upgrade redhat/postfix-pcre-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  14. Upgrade

    Upgrade redhat/postfix-perl-scripts to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  15. Upgrade

    Upgrade redhat/postfix-pgsql to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  16. Upgrade

    Upgrade redhat/postfix-pgsql-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  17. Upgrade

    Upgrade redhat/postfix-sqlite to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  18. Upgrade

    Upgrade redhat/postfix-sqlite-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1
  19. Upgrade

    Upgrade redhat/postfix to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  20. Upgrade

    Upgrade redhat/postfix-cdb to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  21. Upgrade

    Upgrade redhat/postfix-cdb-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  22. Upgrade

    Upgrade redhat/postfix-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  23. Upgrade

    Upgrade redhat/postfix-debugsource to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  24. Upgrade

    Upgrade redhat/postfix-ldap to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  25. Upgrade

    Upgrade redhat/postfix-ldap-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  26. Upgrade

    Upgrade redhat/postfix-lmdb to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  27. Upgrade

    Upgrade redhat/postfix-lmdb-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  28. Upgrade

    Upgrade redhat/postfix-mysql to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  29. Upgrade

    Upgrade redhat/postfix-mysql-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  30. Upgrade

    Upgrade redhat/postfix-pcre to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  31. Upgrade

    Upgrade redhat/postfix-pcre-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  32. Upgrade

    Upgrade redhat/postfix-perl-scripts to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  33. Upgrade

    Upgrade redhat/postfix-pgsql to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  34. Upgrade

    Upgrade redhat/postfix-pgsql-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  35. Upgrade

    Upgrade redhat/postfix-sqlite to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa
  36. Upgrade

    Upgrade redhat/postfix-sqlite-debuginfo to a version that resolves this vulnerability.

    Fixed in 3.8.5-8.el10_0.1.aa

Event History

Aug 6, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·10:37 PM
Data Sourced
via Red Hat·10:37 PM
Severity
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Frequently Asked Questions

1

What is the severity of RHSA-2026:51436?

The severity of RHSA-2026:51436 is high, rated at 7.

2

What security issue does RHSA-2026:51436 address?

RHSA-2026:51436 addresses a buffer over-read vulnerability via malformed enhanced status code (CVE-2026-43964).

3

How do I fix RHSA-2026:51436?

To fix RHSA-2026:51436, you should update the affected postfix packages to the latest version.

4

Which software packages are affected by RHSA-2026:51436?

The affected software packages include redhat/postfix, redhat/postfix-cdb, and redhat/postfix-ldap, among others.

5

When was RHSA-2026:51436 published?

RHSA-2026:51436 was published on August 6, 2026.

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