PT-2026-31027 · Botan · Botan

Nicholas Carlini · Published 2026-04-07 · Updated 2026-04-07 · CVE-2026-34580

Positive Technologies · (AI Summary)

CVSS v4.0

9.3

Critical

AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Name of the Vulnerable Software and Affected Versions Botan versions prior to 3.11.1

Description The Botan cryptography library contains a flaw in the Certificate Store::certificate known function. This function incorrectly identifies certificates, returning true if any certificate in the store has a matching Distinguished Name (DN) and Subject Key Identifier (SKI) with the provided certificate, without verifying if the certificates are identical. A subsequent extension of path validation logic incorrectly assumed that certificate known only returned true for identical certificates. This allows an end entity certificate to be accepted as a trusted root if its DN and SKI match those of a trusted root certificate.

Recommendations Update to version 3.11.1 or later.

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-34580

Affected Products

Botan

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-34580 · Security Note
• https://github.com/randombit/botan/security/advisories/GHSA-v782-6fq4-q827 · Note
• https://twitter.com/0dayPublishing/status/2041631982640124327 · Twitter Post