{"cve":"CVE-2021-32559","nvd":{"published":"2021-07-06T12:15:21.887","modified":"2026-06-17T03:53:10.577","status":"Analyzed","description":"An integer overflow exists in pywin32 prior to version b301 when adding an access control entry (ACE) to an access control list (ACL) that would cause the size to be greater than 65535 bytes. An attacker who successfully exploited this vulnerability could crash the vulnerable process.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-190"],"references":["https://github.com/fireeye/Vulnerability-Disclosures/blob/master/FEYE-2021-0017/FEYE-2021-0017.md","https://github.com/mhammond/pywin32/issues/1700","https://github.com/mhammond/pywin32/pull/1701","https://github.com/mhammond/pywin32/releases","https://github.com/fireeye/Vulnerability-Disclosures/blob/master/FEYE-2021-0017/FEYE-2021-0017.md"],"products":["mhammond:pywin32"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-32559","score":0.01729,"percentile":0.77586,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-hwfp-hg2m-9vr2","url":"https://osv.dev/vulnerability/GHSA-hwfp-hg2m-9vr2","summary":"Integer overflow in pywin32","modified":"2025-03-27T18:04:19.926409Z","packages":[{"ecosystem":"PyPI","name":"pywin32","purl":"pkg:pypi/pywin32","ranges":["<301"],"fixed":["301"]}]},{"id":"PYSEC-2021-112","url":"https://osv.dev/vulnerability/PYSEC-2021-112","summary":"","modified":"2023-11-08T04:05:54.067128Z","packages":[{"ecosystem":"PyPI","name":"pywin32","purl":"pkg:pypi/pywin32","ranges":["<301"],"fixed":["301"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}