GHSA-8f95-v3jq-cj86: pymonocypher: Potential heap buffer overflow on nb_blocks in argon2i_32 when provided buffer is too small
Impact
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.
Patches
Fixed in 4.0.2.8, which now verifies that nb_blocks is large enough. See 90ff5b1.
Workarounds
Provide a correctly sized nb_blocks buffer.
pymonocypher thanks Haris (hextheshadow) for the vulnerability report, details, and recommended fix.
Details
Original advisory: https://github.com/advisories/GHSA-8f95-v3jq-cj86
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-53720 | coverage & exploitation status | NVD · CVE.org |
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