python-ldap is a lightweight directory access protocol (LDAP) client API for Python. In versions prior to 3.4.5, ldap.dn.escape_dn_chars() escapes \x00 incorrectly by emitting a backslash followed by a literal NUL byte instead of the RFC-4514 hex form \00. Any application that uses this helper to construct DNs from untrusted input can be made to consistently fail before a request is sent to the LDAP server (e.g., AD), resulting in a client-side denial of service. Version 3.4.5 contains a patch for the issue.
https://github.com/python-ldap/python-ldap/security/advisories/GHSA-p34h-wq7j-h5v6
https://github.com/python-ldap/python-ldap/releases/tag/python-ldap-3.4.5
https://github.com/python-ldap/python-ldap/commit/6ea80326a34ee6093219628d7690bced50c49a3f
Published: 2025-10-10
Updated: 2025-10-14
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 6.9
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.0004