# CVE-2026-118769: botan3: Botan is a C++ cryptography library

CVE-2026-118769 is fixed in botan3 on 1 platform by DEBIAN-CVE-2026-118769 (version 3.13.0+dfsg-2), released October 31, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-118769
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0037
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 29, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | botan3 Debian 14 | 3.13.0+dfsg-2 | [DEBIAN-CVE-2026-118769](https://patchblox.com/security/data/fix/linux/debian-cve-2026-118769.md) | Oct 31, 2026 |

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Data as of 2026-11-09T19:38:12Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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