CVE-2026-9648EPSS p9.4%

CVE-2026-9648CVE-2026-9648

Description

The crypton-x509-validation Haskell library fails to enforce X.509 NameConstraints, allowing TLS clients to accept certificates whose Subject Alternative Names fall outside the issuing CA’s permitted subtrees. This oversight enables an attacker who compromises a name-constrained sub-CA to impersonate domains beyond its intended scope.

Scoring

CVSS 9.1 ()
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS0.20% probability of exploitation · percentile 9.4% · 2026-06-19T12:03:05Z
Last modified2026-06-11
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.