Buffer overflow in Exim

CVE-2026-94054

Exim before 4.100.1, when Proxy-Protocol is used with an attacker-controlled proxy, has an out-of-bounds write.

Vulnerability class: Buffer Overflow

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

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

cve@mitre.org

Frequently asked questions

What is CVE-2026-94054?: CVE-2026-94054 is a high-severity vulnerability in Exim, classified under Out-of-bounds Write. CVSS score: 7.0/10. Published 2026-09-19.
How severe is CVE-2026-94054?: High severity. CVSS v3 base score is 7.0 out of 10.