{"id":"CVE-2026-53720","state":"PUBLISHED","title":"pymonocypher: Potential heap buffer overflow on nb_blocks in argon2i_32 when provided buffer is too small","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.","publishedAt":"2026-09-03T15:30:06.690Z","updatedAt":"2026-09-03T15:42:53.741Z","severity":{"score":5.1,"label":"Medium","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["jetperch pymonocypher"],"affected":[{"vendor":"jetperch","product":"pymonocypher","versions":[{"version":"< 4.0.2.8","status":"affected"}]}],"references":["https://github.com/jetperch/pymonocypher/security/advisories/GHSA-8f95-v3jq-cj86","https://github.com/jetperch/pymonocypher/commit/90ff5b13b13b5673c372e188f482d8c172e6ab86","https://github.com/jetperch/pymonocypher/releases/tag/v4.0.2.8"],"weaknesses":["CWE-122","CWE-787","CWE-1284"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53720.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53720","state":"PUBLISHED","datePublished":"2026-09-03T15:30:06.690Z","dateUpdated":"2026-09-03T15:42:53.741Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-10T16:43:31.241Z"},"containers":{"cna":{"title":"pymonocypher: Potential heap buffer overflow on nb_blocks in argon2i_32 when provided buffer is too small","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"jetperch","product":"pymonocypher","versions":[{"version":"< 4.0.2.8","status":"affected"}]}],"references":[{"url":"https://github.com/jetperch/pymonocypher/security/advisories/GHSA-8f95-v3jq-cj86","name":"https://github.com/jetperch/pymonocypher/security/advisories/GHSA-8f95-v3jq-cj86","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/jetperch/pymonocypher/commit/90ff5b13b13b5673c372e188f482d8c172e6ab86","name":"https://github.com/jetperch/pymonocypher/commit/90ff5b13b13b5673c372e188f482d8c172e6ab86","tags":["x_refsource_MISC"]},{"url":"https://github.com/jetperch/pymonocypher/releases/tag/v4.0.2.8","name":"https://github.com/jetperch/pymonocypher/releases/tag/v4.0.2.8","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":5.1,"baseSeverity":"MEDIUM","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-122","lang":"en","description":"CWE-122: Heap-based Buffer Overflow","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-787","lang":"en","description":"CWE-787: Out-of-bounds Write","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-1284","lang":"en","description":"CWE-1284: Improper Validation of Specified Quantity in Input","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-03T15:30:06.690Z"},"source":{"advisory":"GHSA-8f95-v3jq-cj86","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-03T15:42:48.682399Z","id":"CVE-2026-53720","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-03T15:42:53.741Z"}}]}}}