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

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
pyca / cryptography	affected < 46.0.6

CWE

CWE-295

References

https://github.com/pyca/cryptography/security/advisories/GHSA-m959-cc7f-wv43

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

CVE

No English description supplied.

https://www.kb.cert.org/vuls/id/948176