CVE-2026-34580: critical vulnerability in randombit botan
Botan has a certificate authentication bypass due to trust anchor confusion
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.3epss 0.5%
Botan is a C++ cryptography library. In 3.11.0, the function Certificate_Store::certificate_known had a misleading name; it would return true if any certificate in the store had a DN (and subject key identifier, if set) matching that of the argument. It did not check that the cert it found and the cert it was passed were actually the same certificate. In 3.11.0 an extension of path validation logic was made which assumed that certificate_known only returned true if the certificates were in fact identical. The impact is that if an end entity certificate is presented, and its DN (and subject key identifier, if set) match that of any trusted root, the end entity certificate is accepted immediately as if it itself were a trusted root. , This vulnerability is fixed in 3.11.1.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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-2026-118769CRITICALBotan: 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%CVE-2024-39312MEDIUMBotan has an Authorization Error due to Name Constraint Decoding BugEPSS 0.3%