CVE-2026-27448

LOW EPSS 15.1%
Published Mar 18, 20263mo ago · Modified Jun 17, 20261w ago
1.7 CVSS 4.0
Low
Find Similar
Published Mar 18, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
1.7
Exploitability
—
Impact
—
Vector string
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
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
15.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-636

Affected Products 1

VendorProductVersionRange
pyopensslpyopenssl*≥0.14  –  <26.0.0

References 3

  • github.com https://github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/CHANGELOG.rst#L27
    Release Notes
  • github.com https://github.com/pyca/pyopenssl/commit/d41a814759a9fb49584ca8ab3f7295de49a85aa0
    Patch
  • github.com https://github.com/pyca/pyopenssl/security/advisories/GHSA-vp96-hxj8-p424
    Vendor Advisory

Remediation

  • github.com https://github.com/pyca/pyopenssl/commit/d41a814759a9fb49584ca8ab3f7295de49a85aa0
    Patch