---
title: "CVE-2026-69249\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-69249?format=md
keywords: index, follow
---

# CVE-2026-69249

Publication date 3 August 2026

Last updated 7 August 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

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## Description

python-cryptography is a package designed to expose cryptographic
primitives and recipes to Python developers. Prior to 49.0.0, when
resolving invalid certificate chains that include duplicate copies of
self-signed certificates, the processing recursively invokes the same
candidate, leading to an exponential blowup. Although the limitation that
the chain depth cannot exceed a specified maximum depth prevents unbounded
recursion and guarantees termination, an attacker-controlled certificate
chain can lead the processing to easily take more than 5s to reject in
testing. This amplification could form the basis for a resource exhaustion
denial of service attack. The core issue arises in the recursive nature of
build\_chain\_inner, which does not de-duplicate against previously analyzed
candidates. As the correctness of validation is not affected, the integrity
of a system cannot be compromised through this vector, only its
availability. This issue is fixed in 49.0.0.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| python-cryptography | 26.04 LTS resolute | Vulnerable |
| 24.04 LTS noble | Not affected |
| 22.04 LTS jammy | Not affected |
| 20.04 LTS focal | Not affected |
| 18.04 LTS bionic | Not affected |
| 16.04 LTS xenial | Not affected |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v4.0

**Base score**

8.7 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Attack requirements | None |
  | Privileges required | None |
  | User interaction | None |
  | Vulnerable system - Confidentiality impact | None |
  | Vulnerable system - Integrity impact | None |
  | Vulnerable system - Availability impact | High |
  | Subsequent system - Confidentiality impact | None |
  | Subsequent system - Integrity impact | None |
  | Subsequent system - Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.7 · High |
  | Base + Threat score | - |
  | Base + Environmental score | - |
  | Base + Threat + Environmental score | - |

**Vector:** CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-69249)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-69249)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-69249)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-69249)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-69249>
* <https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww>
* <https://github.com/pyca/cryptography/pull/14960>
* <https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582>