CVSS 4.0
5.1 mediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:NCVE-2026-53720
Medium (5.1). EPSS 0.2% chance of exploitation in the next 30 days. Fixed in pymonocypher 4.0.2.8.
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.
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 7% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-122, CWE-787, CWE-1284
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-8f95-v3jq-cj86 | PyPI | pymonocypher | <4.0.2.8 | 4.0.2.8 |
| PYSEC-2026-3000 | PyPI | pymonocypher | <4.0.2.8 | 4.0.2.8 |