CVE-2026-69249
Description
A flaw was found in python-cryptography. When processing invalid certificate chains that include duplicate self-signed certificates, the system recursively invokes the same certificate, leading to an exponential increase in processing time. A remote attacker could exploit this by providing a specially crafted certificate chain, causing resource exhaustion and a denial of service (DoS) condition, making the system unavailable. The integrity of the system's validation is not affected, only its availability.
Statement
Red Hat rates this Important (CVSS 3.1 7.5). Duplicate self-signed intermediates can make PolicyBuilder path-building take seconds per request. GitHub CNA CVSS 4.0 is 8.7.
Mitigation
The Rust PolicyBuilder verifier was introduced in cryptography 42.0.0 and this issue was fixed in 49.0.0 (signature-check budget of 128).
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | 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 | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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