RHSA-2026:51034: 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 for x86_64 - Extended Life Cycle Long Life
Red Hat Red Hat Enterprise Linux Server - AUS
redhat/postfix<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-cdb<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-cdb-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-debugsource<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-ldap<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-ldap-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-lmdb-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-mysql<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-mysql-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-pcre<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-pcre-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-perl-scripts<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-pgsql<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-pgsql-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-sqlite<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1
redhat/postfix-sqlite-debuginfo<3.5.8-1.el8_4.1
3.5.8-1.el8_4.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  2. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  3. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  4. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  5. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  6. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  7. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  8. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  9. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  10. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  11. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  12. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  13. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  14. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  15. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  16. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1
  17. Upgrade

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

    Fixed in 3.5.8-1.el8_4.1

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·07:31 AM
Data Sourced
via Red Hat·07:31 AM
Severity
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of RHSA-2026:51034?

The severity of RHSA-2026:51034 is rated as high with a score of 7.

2

How do I fix RHSA-2026:51034?

To fix RHSA-2026:51034, update the postfix packages on your system.

3

What security issue does RHSA-2026:51034 address?

RHSA-2026:51034 addresses a buffer over-read vulnerability via malformed enhanced status code identified as CVE-2026-43964.

4

What software is affected by RHSA-2026:51034?

RHSA-2026:51034 affects the postfix package in Red Hat Enterprise Linux for x86_64 and its Extended Life Cycle Long Life versions.

5

When was RHSA-2026:51034 published?

RHSA-2026:51034 was published on August 6, 2026.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203