Vulnerability details
CVE-2026-118769
randombit botan
Botan: Integer overflow when reporting block size in FFI can cause memory corruption
CVSS 4.0
9.2Critical
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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.2Critical | 4.0 | CVEProject cvelistV5 (CNA) (GitHub_M) | 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 |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| randombit | botan | >= 2.1.0, < 3.13.0 | CVEProject cvelistV5 (CNA) |
References and advisories
3- https://github.com/randombit/botan/security/advisories/GHSA-c68p-822g-jfvr x_refsource_CONFIRM
- https://github.com/randombit/botan/pull/5805 x_refsource_MISC
- https://github.com/randombit/botan/commit/c6089ab7fab616517d56c447c93e13a5c57a0af3 x_refsource_MISC
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Details
- Published
- 2026-10-29
- Last updated
- 2026-10-29
- State
- Published
- Assigner (CNA)
- GitHub_M
- Kolun priority
- 22 · Low
Exploit prediction (EPSS)
0.36%
Probability of exploitation in 30 days
30.6%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-125Out-of-bounds Read
- CWE-681Incorrect Conversion between Numeric Types
- CWE-787Out-of-bounds Write