by Kastro
Paper/Archive/CVE-2026-118769

CVE-2026-118769

randombit botan — Botan: Integer overflow when reporting block size in FFI can cause memory corruption

CVSS 9.2
critical.is priorityof 100
28
CVSS 9.2 (CNA)9.2 / 10 × 3027.6Not in CISA KEV+300.0No EPSS score.000 × 200.0No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
botan>= 2.1.0, < 3.13.0–CNA

Scores by source

GitHub_M (CNA)9.2CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/randombit/botan/security/advisories/GHSA-c68p-822g-jfvrrefgithub.com/randombit/botan/pull/5805refgithub.com/randombit/botan/commit/c6089ab7fab616517d56c447c93e13a5c57a0af3