CVE-2025-67896 Memory corruption in Exim
Remote attackers can trigger a heap-based buffer overflow in Exim mail servers with specific rate-limit settings, potentially leading to code execution or service disruption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-67896?
CVE-2025-67896 is a high-severity memory corruption vulnerability in Exim Exim, published on 14 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Exim before 4.99.1, with certain non-default rate-limit configurations, allows a remote heap-based buffer overflow because database records are cast directly to internal structures without validation.
Weakness: CWE-122
Which versions are affected by CVE-2025-67896?
It affects 1 product.
Products include Exim Exim.
How do I fix CVE-2025-67896?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-67896 being exploited?
There is no known exploitation of CVE-2025-67896 in the wild and no public exploit code.
Other vulnerabilities in Exim Exim
Sources
Also known as DEBIAN-CVE-2025-67896, GHSA-6qxw-x3vc-phrg.