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 Details
- CVSS 4.0 Base Score: 1.7 (LOW)
- CVSS 4.0 Vector: (CVSS: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:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
- CVSS 3.1 Base Score: 5.3
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade py3-openssl | Apr 27, 2026 | Mar 17, 2026 |
| Debian | — | Upgrade pyopenssl | Jul 23, 2026 | Jul 23, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Mar 17, 2026 |
| Ubuntu | — | Upgrade python3-opensslUpgrade python3-openssl (Ubuntu Pro)Upgrade python-openssl (Ubuntu Pro) | Mar 24, 2026 | Mar 23, 2026 |
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