Buffer overflow in Exim
CVE-2025-67896
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L.
EPSS exploit prediction
EPSS: 0.005 (38.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000
Affected products
- Exim — versions 4.99
Weakness classification (CWE)
References
- www.openwall.com/lists/oss-security/2025/12/11/2 (Mailing List)
- exim.org/static/doc/security/ (Vendor Advisory)
- exim.org/static/doc/security/EXIM-Security-2025-12-09.1/report.txt (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List)
Frequently asked questions
- What is CVE-2025-67896?
- CVE-2025-67896 is a high-severity vulnerability in Exim, classified under Heap-based Buffer Overflow. CVSS score: 7.0/10. Published 2025-12-14.
- How severe is CVE-2025-67896?
- High severity. CVSS v3 base score is 7.0 out of 10.