CVE-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.

PUBLISHED Reserved 2026-05-26 | Published 2026-06-11 | Updated 2026-06-11 | Assigner certcc

Problem types

CWE-295: Improper Certificate Validation

Product status

References

www.kb.cert.org/vuls/id/862559

github.com/kazu-yamamoto/crypton-certificate/pull/30

github.com/...anges/f4b77edf6ead77f4a886da40e41eab20f0180e39

hackage.haskell.org/...pton-x509-validation-1.9.1/revisions/

github.com/haskell/security-advisories/pull/332

cve.org (CVE-2026-9648)

nvd.nist.gov (CVE-2026-9648)

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