What is CVE-2026-9648?

CVE-2026-9648 is a critical-severity vulnerability in Haskell Programming Language Crypton-certificate, classified under CWE-295: IMPROPER CERTIFICATE VALIDATION. CVSS score: 9.1/10. Published 2026-06-11.

How severe is CVE-2026-9648?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Haskell Programming Language Crypton-certificate

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 att…

EPSS: 0.002 (13.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Haskell Programming Language Crypton-certificate — versions 0

References

cret@cert.org
cret@cert.org
cret@cert.org
cret@cert.org
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2026-9648?: CVE-2026-9648 is a critical-severity vulnerability in Haskell Programming Language Crypton-certificate, classified under CWE-295: IMPROPER CERTIFICATE VALIDATION. CVSS score: 9.1/10. Published 2026-06-11.
How severe is CVE-2026-9648?: Critical severity. CVSS v3 base score is 9.1 out of 10.