Vulnerability in cryptography (CVE-2026-69248)
Summary
Vulnerability in cryptography (CVE-2026-69248). Risk of unauthorized operations or information disclosure. Exploitable via foo.example.com. Mitigation: upgrade to 49.0.0 or later.
Original description
The description as published by the source.
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.Basi…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-69248 has been found in cryptography.
Attackers can target a specific entry point like foo.example.com over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade cryptography to 49.0.0 or later.
If unsure, ask your IT team or search "cryptography CVE-2026-69248" on the vendor's site.
CVE-2026-69248 (cryptography) — CWE-295
Attack surface: foo.example.com / bar.example.com
Patched: 49.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-295) exists in cryptography. Attackers reach the vulnerable code path via foo.example.com.
Check the vendor advisory for the affected versions of cryptography. Attack surface: foo.example.com / bar.example.com.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 49.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'cryptography' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'cryptography' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
cryptographyを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade cryptography to 49.0.0ステージング環境で 49.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-69248 python-cryptography
References
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com