What is CVE-2026-40687?

CVE-2026-40687 is a medium-severity vulnerability in Exim, classified under CWE-909. CVSS score: 4.8/10. Published 2026-04-30.

How severe is CVE-2026-40687?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Vulnerability in Exim

CVE-2026-40687

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialize…

EPSS: 0.002 (39.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L.

Affected products

Exim — versions 0

Weakness classification (CWE)

CWE-909

References

cve@mitre.org (Mailing List, Third Party Advisory)
cve@mitre.org (Vendor Advisory)
cve@mitre.org (Patch)
cve@mitre.org (Broken Link)

Frequently asked questions

What is CVE-2026-40687?: CVE-2026-40687 is a medium-severity vulnerability in Exim, classified under CWE-909. CVSS score: 4.8/10. Published 2026-04-30.
How severe is CVE-2026-40687?: Medium severity. CVSS v3 base score is 4.8 out of 10.