CVE-2021-32559: Mhammond PYWIN32

Medium severity, CVSS 6.5. EPSS: 1.7% chance of exploitation in the next 30 days.

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.

Affected products

• Mhammond PYWIN32: before 301 (fixed in 301)

Published 2021-07-06. Last modified 2026-06-17.