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.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://exim.org/static/doc/security/ Vendor Advisory
- https://exim.org/static/doc/security/EXIM-Security-2025-12-09.1/report.txt Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 9.8 · eximNVD modified 2026-10-14 13:10
Affected (CPE criteria) 1
cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*
References 5
- https://exim.org/static/doc/security/ Vendor Advisory
- https://exim.org/static/doc/security/EXIM-Security-2025-12-09.1/report.txt Vendor Advisory
- https://www.openwall.com/lists/oss-security/2025/12/11/2 Mailing List
- http://www.openwall.com/lists/oss-security/2025/12/14/1 Mailing List
- http://www.openwall.com/lists/oss-security/2025/12/18/3 Mailing List