CVE-2026-9648
CVE-2026-9648

9.1CRITICAL

Key Information:

Vendor

Haskell Programming Language

Status
Crypton-certificate
Vendor
CVE Published:
11 June 2026

What is CVE-2026-9648?

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.

Affected Version(s)

crypton-certificate 0 < 1.9.1

References

https://github.com/kazu-yamamoto/crypton-certificate/pull/30
https://github.com/kazu-yamamoto/crypton-certificate/pull...
https://hackage.haskell.org/package/crypton-x509-validati...

CVSS V3.1

Score:
9.1
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.