CVE-2026-118769
Botan: Integer overflow when reporting block size in FFI can cause memory corruption
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan 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 the FFI raw ECB mode, an attacker can select the variable-block-size Lion cipher so that the reported size is truncated, the caller allocates insufficient memory, and later block processing causes memory corruption. The C++ API and normally used C API modes such as CBC and CTR are unaffected. This issue is fixed in version 3.13.0.
| CWE | CWE-125 CWE-681 CWE-787 |
| Vendor | randombit |
| Product | botan |
| Published | Oct 29, 2026 |
| Last Updated | Oct 29, 2026 |
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Affected Versions
randombit / botan
>= 2.1.0, < 3.13.0