CVE-2026-53720
Medium
Description
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.
SeverityMedium
CVSS5.1
Exploit probability—
ProductPymonocypher
PublishedSep 3, 2026
First seenSep 3, 2026
How to fix
Update
- pymonocypher4.0.2.8 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| pymonocypherPyPI | v < 4.0.2.8 | 4.0.2.8 |
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