CVE-2026-69248

python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees

State
Published
Severity
6.9 Medium
Published
Aug 3, 2026
Updated
Sep 2, 2026
Reserved
Aug 3, 2026

Read the record on cve.org

Description

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 45.0.0 through 48.0.0, if an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of *.example.com, python-cryptography's verifier accepts which allows escaping outside of the permitted names. The core issue is in DNSConstraint::matches, where a wildcard pattern was treated as matching a more-specific permitted constraint even though *.example.com can expand to sibling names such as bar.example.com outside foo.example.com. This allows acceptance of an invalid certificate chain. This issue is fixed in 49.0.0.

Scores

CVSSScoreVectorSource
4.06.9 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:PGitHub_M

Weaknesses

  • CWE-295 Improper Certificate Validation

Affected Products

ProductVersions
cryptographypyca
  • < 49.0.0Affected

References

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