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.

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

EPSS: 0.001 (22.6th percentile) — read the EPSS interpretation.

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.

Affected products

Exim — versions 4.99

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

www.openwall.com/lists/oss-security/2025/12/11/2
exim.org/static/doc/security/
exim.org/static/doc/security/EXIM-Security-2025-12-09.1/report.txt

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.