CVE-2026-118769 Botan: Integer overflow when reporting block size in FFI can cause memory corruption
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-118769?
CVE-2026-118769 is a critical vulnerability in randombit botan, published on 29 Oct 2026.
Official description
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.
Which versions are affected by CVE-2026-118769?
How do I fix CVE-2026-118769?
No fix has been published for CVE-2026-118769 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-118769 being exploited?
There is no known exploitation of CVE-2026-118769 in the wild and no public exploit code.
Sources
Also known as GHSA-c68p-822g-jfvr.