CVE-2026-9648 CVE-2026-9648
Attackers can bypass X.509 NameConstraints to impersonate domains outside a sub-CA's permitted scope using compromised certificates.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-9648?
CVE-2026-9648 is a critical vulnerability in Haskell Programming Language crypton-certificate, published on 11 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-9648?
4 open source packages ship an affected version, including crypton-x509, crypton-x509-validation and x509.
| Package | Affected | Fixed in |
|---|---|---|
crypton-x509 Hackage | From 1.7.6 | 1.9.1 |
crypton-x509-validation Hackage | From 1.6.12 | 1.9.1 |
x509 Hackage | From 1.4.0 | None |
x509-validation Hackage | From 1.4.0 | None |
Linux distribution packages (10)
ghc-aws openSUSE:Tumbleweed | All versions | 0.25.2-1.1 |
ghc-crypton-asn1-encoding openSUSE:Tumbleweed | All versions | 0.10.0-1.1 |
ghc-crypton-asn1-parse openSUSE:Tumbleweed | All versions | 0.10.0-1.1 |
ghc-crypton-asn1-types openSUSE:Tumbleweed | All versions | 0.4.1-1.1 |
ghc-crypton-pem openSUSE:Tumbleweed | All versions | 0.3.0-1.1 |
ghc-crypton-x509 openSUSE:Tumbleweed | All versions | 1.9.1-1.1 |
ghc-crypton-x509-store openSUSE:Tumbleweed | All versions | 1.9.0-1.1 |
ghc-crypton-x509-system openSUSE:Tumbleweed | All versions | 1.9.0-1.1 |
ghc-crypton-x509-validation openSUSE:Tumbleweed | All versions | 1.9.1-1.1 |
git-annex openSUSE:Tumbleweed | All versions | 10.20260601-2.1 |
How do I fix CVE-2026-9648?
Upgrade crypton-x509 to 1.9.1 or later.
Is CVE-2026-9648 being exploited?
There is no known exploitation of CVE-2026-9648 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-9648, GHSA-7jx5-vvgh-vcjw, HSEC-2026-0008, UBUNTU-CVE-2026-9648, openSUSE-SU-2026:11077-1, openSUSE-SU-2026:11078-1 and 8 more.