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


- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-w8gj-5xrm-gvrp

## What is CVE-2026-118767?

CVE-2026-118767 is a medium-severity vulnerability in randombit botan, published on 29 Oct 2026. 

### Official 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.

Weakness: CWE-158 (Improper Neutralization of Null Byte or NUL Character)

## Which versions are affected by CVE-2026-118767?


## How do I fix CVE-2026-118767?

No fix has been published for CVE-2026-118767 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-118767 being exploited?

There is no known exploitation of CVE-2026-118767 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-118767 and fix it if it is affected.

What it is: CVE-2026-118767 is a medium-severity vulnerability in randombit botan, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-118767 in the wild and no public exploit code.

Affected product: randombit botan. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-118767/ (Markdown: https://insights.sbomify.com/CVE-2026-118767/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-118767
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-118767
- OSV: https://osv.dev/vulnerability/CVE-2026-118767

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-118767/
Summaries are generated and may contain mistakes; the official description above is the record.