CVSS 4.0
1.7 lowCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:UCVE-2026-27448
Low (1.7) in pyopenssl pyopenssl. EPSS 0.3% chance of exploitation in the next 30 days. Fixed in pyopenssl 26.0.0.
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.
Severity
CVSS 3.1
5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 16% of CVEs (scores of 2026-10-31)
- CWE
- CWE-636
- Published
- Modified
- Record from
- the NVD, synced
Affected
- pyopenssl:pyopenssl
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-vp96-hxj8-p424 | PyPI | pyopenssl | >=0.14.0 <26.0.0 | 26.0.0 |
| PYSEC-2026-2268 | PyPI | pyopenssl | >=0.14 <26.0.0 | 26.0.0 |