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Vulnerabilities

Vulnerability · CVE-2026-9648

crypton-x509-validation and crypton-x509 do not enforce X.509 Name Constraints

Published Jun 3, 2026 · catalog updated Jun 3, 2026 · crypton-x509-validation and crypton-x509 do

Check if you run it

No confirmed exploitation is on record for CVE-2026-9648. EPSS is 0.32%. Act only if a listed version of crypton-x509-validation and crypton-x509 do is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (crypton-x509-validation and crypton-x509 do).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.32%
Remediation
Advisory link
Affected products
Hackage crypton-x509 · Hackage crypton-x509-validation · Hackage x509 · Hackage x509-validation

# crypton-x509-validation and crypton-x509 do not enforce X.509 Name Constraints The and libraries did not enforce the X.509 Name Constraints extension during certificate validation. The Name Constraints extension is a critical X.509 extension that restricts the namespace (permitted and excluded subtrees) for which a CA is authorized to issue certificates. Without this enforcement, a TLS client would accept certificates with Subject Alternative Names (SANs) that fall outside the issuing CA's permitted subtrees. An attacker with access to a name-constrained sub-CA's private key could therefore issue certificates for domains outside the sub-CA's intended scope, enabling impersonation of arbitrary domains and man-in-the-middle attacks on TLS connections. The older and packages are also affected but are no longer maintained and have no fix available. This issue was fixed in and .

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Hackage crypton-x5091.7.6 → 1.9.1
  • Hackage crypton-x509-validation1.6.12 → 1.9.1
  • Hackage x5091.4.0, 1.4.1, 1.4.10
  • Hackage x509from 1.4.0
  • Hackage x509-validation1.4.0, 1.4.1, 1.4.2
  • Hackage x509-validationfrom 1.4.0

How to fix CVE-2026-9648

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-9648. EPSS is 0.32%. Act only if a listed version of crypton-x509-validation and crypton-x509 do is installed.

Which versions are affected?

Compare what you have installed with 1.7.6 → 1.9.1, 1.6.12 → 1.9.1, 1.4.0, 1.4.1, 1.4.10, from 1.4.0, 1.4.0, 1.4.1, 1.4.2. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.32%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 3, 2026 · OpenSSF OSV / OSV Scanner

    Detected

    # crypton-x509-validation and crypton-x509 do not enforce X.509 Name Constraints The and libraries did not enforce the X.509 Name Constraints extension during certificate validation. The Name Constraints extension is a critical X.509 extension that restricts the namespace (permitted and excluded subtrees) for which a CA is authorized to issue certificates. Without this enforcement, a TLS client wo

  2. Jun 3, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    crypton-x509-validation fixed in 1.9.1; crypton-x509 fixed in 1.9.1

  3. Jun 3, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    crypton-x509-validation fixed in 1.9.1

  4. Jun 3, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    crypton-x509 fixed in 1.9.1

  5. Jun 3, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    # crypton-x509-validation and crypton-x509 do not enforce X.509 Name Constraints The and libraries did not enforce the X.509 Name Constraints extension during certificate validation. The Name Constraints extension is a critical X.509 extension that restricts the namespace (permitted and excluded subtrees) for which a CA is authorized to issue certificates. Without this enforcement, a TLS client wo

Sources

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.