CVE-2026-34582
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk14th percentile - higher than 14% of all known CVEs
Summary
In Botan's TLS 1.3 implementation before version 3.11.1, ApplicationData records can be processed before the Finished message is received. This allows a client to bypass certificate-based authentication.
Risk Assessment
Servers requiring client certificate authentication can be bypassed, allowing unauthorized clients to access protected resources.
Recommendation
Update Botan to version 3.11.1 or later.
Original NVD description (English source)
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.