CVE-2026-34073 LOW

CVE-2026-34073: cryptography has incomplete DNS name constraint enforcement on peer names

Vendor Pyca
Product cryptography
Weakness CWE-295
Published March 31, 2026
Last update March 31, 2026

CVSS base score

1.7/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U

What the vulnerability does

01Description

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to version 46.0.6, DNS name constraints were only validated against SANs within child certificates, and not the "peer name" presented during each validation. Consequently, cryptography would allow a peer named bar.example.com to validate against a wildcard leaf certificate for *.example.com, even if the leaf's parent certificate (or upwards) contained an excluded subtree constraint for bar.example.com. This issue has been patched in version 46.0.6.

Key dates

02Disclosure timeline

March 31, 2026 CVE published
March 31, 2026 Record updated