medium5.1
CVE-2026-53720
pymonocypher: Potential heap buffer overflow on nb_blocks in argon2i_32 when provided buffer is too small
Impact
pymonocypher uses cython to wrap the Monocypher C library. Prior to version 4.0.2.8, the argon2i_32 implementation does not check the nb_blocks size. If the caller does not provide a sufficiently large buffer based on the API contract, then argon2i_32 will write past the end of the buffer and possibly corrupt the heap. This issue has been patched in version 4.0.2.8.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pymonocypher | < 4.0.2.8 | 4.0.2.8 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-8f95-v3jq-cj86
- https://github.com/jetperch/pymonocypher/security/advisories/GHSA-8f95-v3jq-cj86
- https://github.com/jetperch/pymonocypher/commit/90ff5b13b13b5673c372e188f482d8c172e6ab86
- https://github.com/jetperch/pymonocypher/releases/tag/v4.0.2.8