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9.2 Critical

Botan is a C++ cryptography library.

CVE-2026-118769

Botan is a C++ cryptography library. From 2.1.0 until 3.13.0, the Botan C API function botanblockcipherblocksize converted a sizet 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.

Assessment

CVSS
9.2 (v4.0)
Severity
Critical
Known exploited
Not listed in CISA KEV
Exploit availability
Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published
29 October 2026
Last updated
30 October 2026
Weakness
CWE-125, CWE-681, CWE-787
Assigner
security-advisories@github.com

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

At the source

References

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