9.1

CVE-2026-9648: haskell programming language crypton-certificate

CVSS: 9.1v3.1CriticalDeferred
AliasesUBUNTU-CVE-2026-9648DEBIAN-CVE-2026-9648openSUSE-SU-2026:11077-1
Published 11-06-2026Last modified 11-06-2026
Open JSON

Vulnerability summary

CVE-2026-9648 is a critical (CVSS 9.1) vulnerability in haskell programming language crypton-certificate. EPSS estimates a 0.32% chance of exploitation in the next 30 days, higher than 23.5% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.32%
0%100%
Low · +0.10 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 11-06-2026
    PublishedVulnerability first disclosed.
  2. 11-06-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.32%

Chance of exploitation in the next 30 days

Percentile

24%

Versus all other CVEs

30-day change

+0.10 pp

From 0.22% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.32%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Opensuse10 products
  • ghc-aws&distro=openSUSE Tumbleweed< 0.25.2-1.1
  • ghc-crypton-asn1-encoding&distro=openSUSE Tumbleweed< 0.10.0-1.1
  • ghc-crypton-asn1-parse&distro=openSUSE Tumbleweed< 0.10.0-1.1
  • ghc-crypton-asn1-types&distro=openSUSE Tumbleweed< 0.4.1-1.1
  • ghc-crypton-pem&distro=openSUSE Tumbleweed< 0.3.0-1.1
Debian2 products
  • haskell-crypton-x509All versions (No fix recorded)
  • haskell-crypton-x509-validationAll versions (No fix recorded)
Haskell programming language1 product
Ubuntu1 product
  • haskell-crypton-x509-validationAll versions (No fix recorded)

4 vendors · 14 products

References

9 links