CVE-2026-69248
Description
A flaw was found in python-cryptography. This vulnerability arises from incorrect handling of wildcard Domain Name System (DNS) names during certificate validation. Specifically, the verifier may accept a certificate with a broad wildcard DNS name (e.g., *.example.com) even when a more restrictive name (e.g., foo.example.com) is permitted by an intermediate Certificate Authority (CA). This misinterpretation allows an attacker to bypass certificate validation, potentially leading to the acceptance of invalid certificates and enabling unauthorized access or spoofing.
Statement
Red Hat rates this Moderate (CVSS 3.1 7.4). Exploitation requires a DNS-constrained intermediate CA that issues a broader wildcard leaf SAN than its permitted subtree, which Web PKI does not use. GitHub CNA CVSS 4.0 is 6.9. This is distinct from CVE-2026-34073 (wildcard SAN vs peer-name constraints, fixed in 46.0.6).
Mitigation
The Rust PolicyBuilder verifier was introduced in cryptography 42.0.0 and this issue was fixed in 49.0.0.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Integrity,Authentication
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The product might connect to a malicious host while believing it is a trusted host, or the product might be deceived into accepting spoofed data that appears to originate from a trusted host.
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