---
id: CVE-2026-118767
title: 'Botan: Python binding bcrypt APIs truncate passwords containing embedded NULs'
summary: >-
  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 p…
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-158
vendor: randombit
product: botan
affected:
  - 'botan >= 1.11.22, < 3.13.0'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-30T15:20:33.590831Z'
published: '2026-10-29'
updated: '2026-10-30'
sourceUpdated: '2026-10-30T17:12:36.136Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-118767'
references:
  - url: 'https://github.com/randombit/botan/security/advisories/GHSA-w8gj-5xrm-gvrp'
    label: 'https://github.com/randombit/botan/security/advisories/GHSA-w8gj-5xrm-gvrp'
  - url: 'https://github.com/randombit/botan/pull/5814'
    label: 'https://github.com/randombit/botan/pull/5814'
  - url: >-
      https://github.com/randombit/botan/commit/5a4ac737e72e18a08eca848049e3dd38571c73b4
    label: >-
      https://github.com/randombit/botan/commit/5a4ac737e72e18a08eca848049e3dd38571c73b4
tags:
  - cve.org
epss: 0.00217
epssPercentile: 0.12326
ingestedAt: '2026-11-05T16:24:31.135Z'
---

## Overview

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.

## Affected

- `botan >= 1.11.22, < 3.13.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.