CVE-2026-9648: Haskell Programming Language crypton-certificate · Improper Certificate Validation
Affects Haskell Programming Language crypton-certificateSource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical : upgrade to 1.9.1 as a priority.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 11 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade Haskell Programming Language crypton-certificate to 1.9.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Haskell Programming Languagecrypton-certificate | Affected
| Fixed in
|
AI-suggested
If you cannot patch yet, users should consider alternative certificate validation methods or libraries that properly enforce X.509 NameConstraints.
Description
The crypton-x509-validation Haskell library does not properly enforce X.509 NameConstraints, allowing TLS clients to accept certificates with Subject Alternative Names outside the permitted subtrees of the issuing CA. This vulnerability enables an attacker who compromises a name-constrained sub-CA to impersonate domains beyond its intended scope. The issue is classified under CWE-295 (Improper Certificate Validation) and has a critical CVSS score of 9.1.
References
- github.com/kazu-yamamoto/crypton-certificate/pull/30 (opens in a new tab)
- github.com/kazu-yamamoto/crypton-certificate/pull/30/changes/f4b77edf6ead77f4a886da40e41eab20f0180e39 (opens in a new tab)
- hackage.haskell.org/package/crypton-x509-validation-1.9.1/revisions/ (opens in a new tab)
- github.com/haskell/security-advisories/pull/332 (opens in a new tab)
- kb.cert.org/vuls/id/862559 (opens in a new tab)