What is CVE-2026-94056?

CVE-2026-94056 is a high-severity vulnerability in Exim, classified under Use of Uninitialized Resource. CVSS score: 7.5/10. Published 2026-09-19.

How severe is CVE-2026-94056?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Exim

CVE-2026-94056

Exim before 4.100.1, when Proxy-Protocol is used with an attacker-controlled proxy, allows attackers to read certain uninitialized data from stack memory.

Published 2026-09-19 · last modified 2026-09-24.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:L.

EPSS exploit prediction

EPSS: 0.002 (15.0th percentile), scored 2026-11-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Exim

Weakness classification (CWE)

CWE-908 — Use of Uninitialized Resource

References

lists.exim.org/lurker/message/20260918.121220.0f87338e.en.html (Vendor Advisory)

Frequently asked questions

What is CVE-2026-94056?: CVE-2026-94056 is a high-severity vulnerability in Exim, classified under Use of Uninitialized Resource. CVSS score: 7.5/10. Published 2026-09-19.
How severe is CVE-2026-94056?: High severity. CVSS v3 base score is 7.5 out of 10.