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.
Published: 2026-09-03
Score: 5.1 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-8f95-v3jq-cj86 pymonocypher: Potential heap buffer overflow on nb_blocks in argon2i_32 when provided buffer is too small
History

Fri, 04 Sep 2026 16:00:00 +0000

Type Values Removed Values Added
First Time appeared Jetperch
Jetperch pymonocypher
Vendors & Products Jetperch
Jetperch pymonocypher

Fri, 04 Sep 2026 09:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 03 Sep 2026 15:45:00 +0000

Type Values Removed Values Added
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.
Title pymonocypher: Potential heap buffer overflow on nb_blocks in argon2i_32 when provided buffer is too small
Weaknesses CWE-122
CWE-1284
CWE-787
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}


Subscriptions

Jetperch Pymonocypher
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-03T15:42:53.741Z

Reserved: 2026-06-10T16:43:31.241Z

Link: CVE-2026-53720

cve-icon Vulnrichment

Updated: 2026-09-03T15:42:51.390Z

cve-icon NVD

Status : Received

Published: 2026-09-03T16:17:25.360

Modified: 2026-09-03T16:17:25.360

Link: CVE-2026-53720

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-04T15:40:22Z

Weaknesses