CVE-2026-53720
Received
Received - Intake
Buffer Overflow in PyMonocypher Argon2i_32 Implementation
Vulnerability report for CVE-2026-53720, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-03
Last updated on: 2026-09-03
Assigner: GitHub, Inc.
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| jetperch | pymonocypher | to 4.0.2.8 (exc) |
| jetperch | pymonocypher | 4.0.2.8 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-1284 | The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties. |
| CWE-122 | A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). |
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
