CVE-2021-46823

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-06-18 · updated 2026-06-17
Weakness: CWE-1333

Description

python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition.

Affected products

python-ldap: before 3.4.0 — fixed in 3.4.0

How to fix

Upgrade to a fixed version: python-ldap 3.4.0. Check the vendor advisory for mitigations.

References

https://exchange.xforce.ibmcloud.com/vulnerabilities/221507
https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm
https://exchange.xforce.ibmcloud.com/vulnerabilities/221507
https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm

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