CVE-2026-43964: High severity Postfix Postfix vulnerability
Last updated 13 May 2026
Other sources
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.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/postfixto a version that resolves this vulnerability.Fixed in 3.11.2-4Fixed in 3.11.3-1 - Upgrade
Upgrade
Postfixto a version that resolves this vulnerability.Fixed in 3.8.16 - Upgrade
Upgrade
Postfixto a version that resolves this vulnerability.Fixed in 3.9.10 - Upgrade
Upgrade
Postfixto a version that resolves this vulnerability.Fixed in 3.10.9
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43964?
CVE-2026-43964 has been classified as a moderate severity vulnerability.
How do I fix CVE-2026-43964?
To fix CVE-2026-43964, update Postfix to version 3.8.16, 3.9.10 or 3.10.9 or later.
What products are affected by CVE-2026-43964?
CVE-2026-43964 affects Postfix versions prior to 3.8.16, 3.9 prior to 3.9.10, and 3.10 prior to 3.10.9.
What type of vulnerability is CVE-2026-43964?
CVE-2026-43964 is a buffer over-read vulnerability that can cause a process crash.
What are the potential impacts of CVE-2026-43964?
The potential impacts of CVE-2026-43964 include the possibility of application instability or crashes.