CVE-2026-34582

Botan has a TLS 1.3 certificate authentication bypass

State: Published
Severity: 8.7 High
Published: Apr 7, 2026
Updated: Jul 15, 2026
Reserved: Mar 30, 2026

Description

Botan is a C++ cryptography library. Prior to version 3.11.1, the TLS 1.3 implementation allowed ApplicationData records to be processed prior to the Finished message being received. A server which is attempting to enforce client authentication via certificates can by bypassed by a client which entirely omits Certificate, CertificateVerify, and the Finished message and instead sends application data records. This vulnerability is fixed in 3.11.1.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N	GitHub_M
3.1	9.1 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	redhat-SADP

Weaknesses

CWE-841 Improper Enforcement of Behavioral Workflow
CWE-166 Improper Handling of Missing Special Element

Affected Products

Product	Versions
botanrandombit	< 3.11.1Affected

References

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