CVE-2026-34073
cryptography has incomplete DNS name constraint enforcement on peer names
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 bar.example.com. This issue has been patched in version 46.0.6.
How to fix CVE-2026-34073
To remediate CVE-2026-34073, upgrade the affected package to a fixed version below.
- —upgrade to 46.0.7-r0 or later
- —no fix listed
- —upgrade to 46.0.6 or later
- —upgrade to 46.0.6 or later
Is CVE-2026-34073 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 46.0.7-r0
- from 0
- from 0, < 46.0.6
- from 0, < 46.0.6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |