CVE-2026-118766
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
In the Botan library, the online OCSP client prior to 3.13.0 allowed a single HTTP redirect while posting an OCSP request to the URI in a certificate's Authority Information Access extension. A malicious OCSP responder or on-path attacker could redirect the client to make one blind request to an otherwise unreachable internal HTTP service, resulting in blind SSRF; response timing can provide a coarse internal-service oracle. The issue is fixed in version 3.13.0.
Risk Assessment
Blind SSRF against internal HTTP services is possible, potentially affecting services with non-idempotent GET handlers. Response timing may serve as a coarse oracle for internal service discovery.
Recommendation
Update Botan to version 3.13.0 or later. Restrict outbound access of OCSP clients to necessary addresses.
Other vulnerabilities in Botan
See all- CVE-2015-7825High
Botan before 1.11.22 improperly validates certificate paths, allowing remote attackers to cause a denial of service via a certificate with a loop in the certificate chain.
- CVE-2015-7824High
Botan versions 1.11.x before 1.11.22 are vulnerable to a padding-oracle attack that allows remote attackers to decrypt TLS ciphertext data using CBC ciphersuites.
- CVE-2016-2850High
Botan versions 1.11.x before 1.11.29 do not enforce TLS policy for signature algorithms and ECC curves, allowing remote attackers to conduct downgrade attacks.
- CVE-2016-2849High
Botan before 1.10.13 and 1.11.x before 1.11.29 do not use a constant-time algorithm to perform a modular inverse on the signature nonce k, which might allow remote attackers to obtain ECDSA secret keys via a timing side-channel attack.
- CVE-2016-2194High
The ressol function in Botan before 1.10.11 and 1.11.x before 1.11.27 allows remote attackers to cause a denial of service (infinite loop) via unspecified input to the OS2ECP function, related to a composite modulus.
- CVE-2015-7827High
Botan before 1.10.13 and 1.11.x before 1.11.22 makes it easier for remote attackers to conduct million-message attacks by measuring time differences related to decoding of PKCS#1 padding.
- CVE-2015-5727High
The BER decoder in Botan 1.10.x before 1.10.10 and 1.11.x before 1.11.19 allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors, related to a length field.
- CVE-2015-5726High
The BER decoder in Botan versions 0.10.x before 1.10.10 and 1.11.x before 1.11.19 allows remote attackers to cause an application crash via an empty BIT STRING in ASN.1 data.
- CVE-2014-9742High
The Miller-Rabin primality check in Botan before 1.10.8 and 1.11.x before 1.11.9 improperly uses a single random base, making it easier for remote attackers to defeat cryptographic protection mechanisms via a DH group.
- CVE-2026-118769Critical
In the Botan C++ cryptography library, the C API function botan_block_cipher_block_size converted a size_t block size to int without a bounds check. In an application that accepts external algorithm parameter strings and uses FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher, causing the reported size to be truncated, insufficient memory allocation, and later memory corruption. The issue is fixed in version 3.13.0.
Original NVD description (English source)
Botan is a C++ cryptography library. Prior to 3.13.0, Botan's online OCSP client allowed a single HTTP redirect while posting an OCSP request to the URI in a certificate's Authority Information Access extension. A malicious OCSP responder or an on-path attacker could redirect the client to make one blind request to an otherwise unreachable internal HTTP service. The primary impact is blind SSRF that might affect internal services with non-idempotent GET handlers, and response timing can provide a coarse internal-service oracle. This issue is fixed in version 3.13.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS