CVE-2026-118769

Name of the Vulnerable Software and Affected Versions Botan versions 2.1.0 through 3.12.x

Description The Botan C API function botan block cipher block size() converts a size t block size to an int without performing a bounds check. In applications that accept external algorithm parameter strings and utilize the Foreign Function Interface (FFI) raw Electronic Codebook (ECB) mode, an attacker can select the variable-block-size Lion cipher. This causes the reported size to be truncated, leading the caller to allocate insufficient memory, which subsequently results in memory corruption during block processing. The C++ API and standard C API modes, such as Cipher Block Chaining (CBC) and Counter (CTR), are not affected.

Recommendations Update to version 3.13.0.