{"id":"CVE-2026-118769","title":"Botan: Integer overflow when reporting block size in FFI can cause memory corruption","summary":"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…","severity":"critical","cvss":9.2,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","cvssSource":"cna","cwe":["CWE-125","CWE-681","CWE-787"],"vendor":"randombit","product":"botan","affected":["botan >= 2.1.0, < 3.13.0"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-29T20:20:31.067238Z"},"published":"2026-10-29","updated":"2026-10-29","sourceUpdated":"2026-10-29T20:21:04.235Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-118769","references":[{"url":"https://github.com/randombit/botan/security/advisories/GHSA-c68p-822g-jfvr","label":"https://github.com/randombit/botan/security/advisories/GHSA-c68p-822g-jfvr"},{"url":"https://github.com/randombit/botan/pull/5805","label":"https://github.com/randombit/botan/pull/5805"},{"url":"https://github.com/randombit/botan/commit/c6089ab7fab616517d56c447c93e13a5c57a0af3","label":"https://github.com/randombit/botan/commit/c6089ab7fab616517d56c447c93e13a5c57a0af3"}],"tags":["cve.org"],"epss":0.00365,"epssPercentile":0.30505,"ingestedAt":"2026-11-03T00:33:31.381Z","slug":"CVE-2026-118769","body":"## Overview\n\nBotan 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.\n\n## Affected\n\n- `botan >= 2.1.0, < 3.13.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":50.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}