CVE-2026-34073

Severity
1.7LOW
EPSS
0.0%
top 94.03%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedMar 31

Description

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 b

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

Affected Packages4 packages

Debianpython-cryptography< 46.0.6-1
PyPIcryptography< 46.0.6
CVEListV5pyca/cryptography< 46.0.6

🔴Vulnerability Details

4
OSV
CVE-2026-34073: cryptography is a package designed to expose cryptographic primitives and recipes to Python developers2026-03-31
CVEList
cryptography has incomplete DNS name constraint enforcement on peer names2026-03-31
OSV
cryptography has incomplete DNS name constraint enforcement on peer names2026-03-27
GHSA
cryptography has incomplete DNS name constraint enforcement on peer names2026-03-27

📋Vendor Advisories

2
Red Hat
cryptography: python: Cryptography: Security bypass due to improper DNS name constraint validation2026-03-31
Debian
CVE-2026-34073: python-cryptography - cryptography is a package designed to expose cryptographic primitives and recipe...2026

🕵️Threat Intelligence

1
Wiz
CVE-2026-34073 Impact, Exploitability, and Mitigation Steps | Wiz

💬Community

4
Bugzilla
CVE-2026-34073 python-cryptography: Cryptography: Security bypass due to improper DNS name constraint validation2026-03-31
Bugzilla
CVE-2026-34073 pypy: Cryptography: Security bypass due to improper DNS name constraint validation [fedora-all]2026-03-31
Bugzilla
CVE-2026-34073 pypy3.10: Cryptography: Security bypass due to improper DNS name constraint validation [fedora-all]2026-03-31
Bugzilla
CVE-2026-34073 pypy3.11: Cryptography: Security bypass due to improper DNS name constraint validation [fedora-all]2026-03-31