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 v3.1 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Checked 2026-11-06 at 22:26 UTC. The most recent advisory here was published 2021-08-09. Updated continuously from NVD, GHSA, OSV and CNA feeds.