# CVE-2026-104267: Botan: scrypt V-buffer heap overflow on 32-bit from constructor-accepted parameters

Status: published. Published: 2026-11-06. Updated: 2026-11-06.

Botan is a C++ cryptography library. From 2.7.0 until 3.13.0, Botan's Scrypt implementation on 32-bit platforms computes required memory with unchecked multiplication, allowing attacker-controlled Scrypt parameters to wrap the allocation size and create a buffer smaller than the algorithm subsequently writes. The issue affects systems that enable Scrypt and accept arbitrary parameters from a hostile source, including applications that decrypt attacker-supplied encrypted private keys. A triggering parameter set can cause approximately four gigabytes of Scrypt output to be written past the allocated heap buffer, immediately crashing the process and causing denial of service. Arbitrary code execution is not demonstrated and appears difficult, but cannot be excluded from the overwrite primitive. This issue is fixed in version 3.13.0.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- randombit / botan: >= 2.7.0, < 3.13.0 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 4.0: 4.1 (medium); CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/randombit/botan/security/advisories/GHSA-36rp-hhp4-wh83 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/randombit/botan/pull/5629 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/randombit/botan/commit/459acdeba242dacc11ad8225e7d3e28203ce4f78 (CNA: GitHub_M; x_refsource_MISC)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-104267; retrieved 2026-11-06; source updated 2026-11-06

Revision: 9b6f5dd33b37cb3f58eb8702af4fab12d858ccd6f64e72fc891986543b35b7ed

Canonical: https://y2.dev/cve/CVE-2026-104267

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