Vulnerability 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.
Related Weaknesses (CWE)
References
- https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a62928
- https://github.com/pyca/cryptography/pull/14960
- https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww
- https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww
FAQ
What is CVE-2026-69249?
CVE-2026-69249 is a documented vulnerability. 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 ...
How severe is CVE-2026-69249?
CVSS scoring is not yet available for CVE-2026-69249. Check NVD for updates.
Is there a patch for CVE-2026-69249?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.