CVE-2026-27459

Description

pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, if a user provided callback to `set_cookie_generate_callback` returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0.0, cookie values that are too long are now rejected.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27459.json

https://github.com/pyca/pyopenssl/security/advisories/GHSA-5pwr-322w-8jr4

https://github.com/pyca/pyopenssl/commit/57f09bb4bb051d3bc2a1abd36e9525313d5cd408

https://github.com/pyca/pyopenssl/blob/358cbf29c4e364c59930e53a270116249581eaa3/CHANGELOG.rst

https://bugzilla.redhat.com/show_bug.cgi?id=2448503

https://access.redhat.com/security/cve/CVE-2026-27459

https://access.redhat.com/errata/RHSA-2026:8437

https://access.redhat.com/errata/RHSA-2026:7224

https://access.redhat.com/errata/RHSA-2026:24853

https://access.redhat.com/errata/RHSA-2026:22465

https://access.redhat.com/errata/RHSA-2026:21017

https://access.redhat.com/errata/RHSA-2026:19375

https://access.redhat.com/errata/RHSA-2026:14874

https://access.redhat.com/errata/RHSA-2026:14873

https://access.redhat.com/errata/RHSA-2026:14835

https://access.redhat.com/errata/RHSA-2026:13553

https://access.redhat.com/errata/RHSA-2026:13545

https://access.redhat.com/errata/RHSA-2026:13512

https://access.redhat.com/errata/RHSA-2026:13508

https://access.redhat.com/errata/RHSA-2026:11996

https://access.redhat.com/errata/RHSA-2026:11916

https://access.redhat.com/errata/RHSA-2026:11856

https://access.redhat.com/errata/RHSA-2026:10754

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS