Buffer overflow in Mtrojnar Osslsigncode

CVE-2026-39853

osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.12, A stack buffer overflow vulnerability exists in osslsigncode in several signature verification paths. During verification of a PKCS#7 signature, t…

Vulnerability class: Buffer Overflow

EPSS: 0.000 (2.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-39853?
CVE-2026-39853 is a high-severity vulnerability in Mtrojnar Osslsigncode, classified under Stack-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-04-09.
How severe is CVE-2026-39853?
High severity. CVSS v3 base score is 7.8 out of 10.