CVE-2026-118767: Botan: Python binding bcrypt APIs truncate passwords containing embedded NULs

Description

Botan is a C++ cryptography library. From 1.11.22 until 3.13.0, Botan's Python binding converted Python strings containing U+0000 to const char* values without consistently rejecting the embedded NUL, causing bcrypt and check_bcrypt to process only the prefix before the NUL. Applications could validate a longer password but hash a shorter effective value, allowing application password-policy bypass; scrypt and argon2 are unaffected. This issue is fixed in version 3.13.0.

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack vector

Network

Complexity

High

Privileges

None

User interaction

None

Confidentiality

Low

Integrity

Low

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

BO

botan · randombit

>= 1.11.22, < 3.13.0 · source: vendor