CVE-2025-67896

low-risk

Published 2025-12-14

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.

Do I need to act?

0.11% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 7.0/10 High

NETWORK / HIGH complexity

Affected Products (1)

Exim

Affected Vendors

Exim

References (5)

Vendor Advisory https://exim.org/static/doc/security/

Vendor Advisory https://exim.org/static/doc/security/EXIM-Security-2025-12-09.1/report.txt

Mailing List 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

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low-risk

Severity 21/34 · High

Exploitability 0/34 · Minimal

Exposure 5/34 · Minimal