CVE-2026-34582: high-severity vulnerability in randombit botan
Botan has a TLS 1.3 certificate authentication bypass
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.2%
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.
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
Affected products
randombit · botanRelated CVEs — randombit botan
In the same product, most dangerous first.
CVE-2024-34702MEDIUMBotan has a Denial of Service Due to Excessive Name ConstraintsEPSS 0.8%CVE-2024-34703HIGHBotan Vulnerable to Denial of Service Due to Overly Large Elliptic Curve ParametersEPSS 0.5%CVE-2026-34580CRITICALBotan has a certificate authentication bypass due to trust anchor confusionEPSS 0.5%CVE-2026-118769CRITICALBotan: Integer overflow when reporting block size in FFI can cause memory corruptionEPSS 0.4%CVE-2026-44378MEDIUMBotan: Quadratic complexity decoding BER indefinite length encodingsEPSS 0.3%CVE-2026-32877HIGHBotan: Heap Buffer Over-read in SM2 Decryption via Undersized C3 Hash FieldEPSS 0.3%