Vulnerability · Published Aug 3, 2026 · Assigned by GitHub_M
CVE-2026-69248python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees
Medium 6.9
In plain English
A medium-severity improper certificate validation in cryptography from pyca. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 45.0.0 through 48.0.0, if an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of *.example.com, python-cryptography's verifier accepts which allows escaping outside of the permitted names. The core issue is in DNSConstraint::matches, where a wildcard pattern was treated as matching a more-specific permitted constraint even though *.example.com can expand to sibling names such as bar.example.com outside foo.example.com. This allows acceptance of an invalid certificate chain. This issue is fixed in 49.0.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | python3.14-cryptography | 45.0.4-4.el10_2.5 | ALSA-2026:64795 |
| AlmaLinux:9 | python3.14-cryptography | 45.0.4-4.el9_8.6 | ALSA-2026:64774 |
| Debian:12 | python-cryptography | no fix listed | DEBIAN-CVE-2026-69248 |
| Debian:13 | python-cryptography | no fix listed | DEBIAN-CVE-2026-69248 |
| Debian:14 | python-cryptography | 49.0.0-1 | DEBIAN-CVE-2026-69248 |
| PyPI | cryptography | 49.0.0 | PYSEC-2026-3554 |
| PyPI | cryptography | 49.0.0 | GHSA-m2h6-j472-rp4c |
| Rocky Linux:10 | python3.14-cryptography | 0:45.0.4-4.el10_2.5 | RLSA-2026:64795 |
| Rocky Linux:9 | python3.14-cryptography | 0:45.0.4-4.el9_8.6 | RLSA-2026:64774 |
| Ubuntu:26.04:LTS | python-cryptography | 46.0.5-1ubuntu2.2 | UBUNTU-CVE-2026-69248 |
| Ubuntu:26.04:LTS | python-cryptography | 46.0.5-1ubuntu2.2 | USN-8776-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| pyca | cryptography | < 49.0.0 |
Weakness: CWE-295 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
References
- https://github.com/pyca/cryptography/security/advisories/GHSA-m2h6-j472-rp4c x_refsource_CONFIRM
- https://github.com/pyca/cryptography/pull/14888 x_refsource_MISC
- https://github.com/pyca/cryptography/commit/4d035a4225965edeffd312079a510ef25fcfdcb2 x_refsource_MISC