RHSA-2026:50963: 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

20 affected componentsFixes available
Red Hat Red Hat Enterprise Linux Server - AUS
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life
redhat/postfix<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-cdb<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-cdb-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-debugsource<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-ldap<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-ldap-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-lmdb-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-mysql<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-mysql-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-pcre<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-pcre-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-perl-scripts<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-pgsql<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-pgsql-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-sqlite<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1
redhat/postfix-sqlite-debuginfo<3.5.8-4.el8_6.1
3.5.8-4.el8_6.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  2. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  3. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  4. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  5. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  6. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  7. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  8. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  9. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  10. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  11. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  12. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  13. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  14. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  15. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  16. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1
  17. Upgrade

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

    Fixed in 3.5.8-4.el8_6.1

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·01:50 AM
Data Sourced
via Red Hat·01:50 AM
Severity
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Frequently Asked Questions

1

What is the severity of RHSA-2026:50963?

The severity of RHSA-2026:50963 is classified as high with a score of 7.

2

What does RHSA-2026:50963 address?

RHSA-2026:50963 addresses a security vulnerability in Postfix that requires an important security update.

3

How do I fix RHSA-2026:50963?

To fix RHSA-2026:50963, you should update your Postfix package to the latest version provided in the security advisory.

4

Who is affected by RHSA-2026:50963?

RHSA-2026:50963 affects users of Red Hat Enterprise Linux Server and Red Hat Enterprise Linux for x86_64.

5

When was RHSA-2026:50963 published?

RHSA-2026:50963 was published on August 6, 2026.

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