Vulnerability Description
pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Pyopenssl | Pyopenssl | >= 0.14, < 26.0.0 |
Related Weaknesses (CWE)
References
- https://github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/Release Notes
- https://github.com/pyca/pyopenssl/commit/d41a814759a9fb49584ca8ab3f7295de49a85aaPatch
- https://github.com/pyca/pyopenssl/security/advisories/GHSA-vp96-hxj8-p424Vendor Advisory
FAQ
What is CVE-2026-27448?
CVE-2026-27448 is a vulnerability with a CVSS score of 5.3 (MEDIUM). pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled ex...
How severe is CVE-2026-27448?
CVE-2026-27448 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-27448?
Check the references section above for vendor advisories and patch information. Affected products include: Pyopenssl Pyopenssl.