CVE-2026-43964
HIGHCVSS 7.5/10EPSS 0.41%
Last modified
CVE-2026-43964 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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.. EPSS estimates a 0.41% chance of exploitation in the next 30 days.
Description
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Postfix | Postfix | < 3.8.16 |
| Postfix | Postfix | >= 3.9.0, < 3.9.10 |
| Postfix | Postfix | >= 3.10.0, < 3.10.9 |
References
- https://www.mail-archive.com/postfix-announce@postfix.org/msg00110.htmlMailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2026/05/04/30Mailing List, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2026-43964?
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.
How severe is CVE-2026-43964?
CVE-2026-43964 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.41% probability of exploitation in the next 30 days.
How do I fix CVE-2026-43964?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2026-43964?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST