Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-46823

23
FAUCET Score

CVE-2021-46823 describes a Regular Expression Denial of Service (ReDoS) vulnerability in python-ldap versions prior to 3.4.0, specifically when the ldap.schema module processes untrusted schema definitions. A remote, authenticated attacker can exploit this flaw by sending crafted regex input, leading to a denial of service condition. The vulnerability is rated Medium severity (CVSS 6.5), requiring network access and low privileges, with a high impact on availability. There is no evidence of active exploitation, publicly available exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
< 3.4.0CPE matchmatch criteria
cpe:2.3:a:python-ldap:python-ldap:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.5MEDIUM

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 Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.71%
Probability of exploitation in next 30 days
EPSS Percentile
75.0%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0171 is in the 88th percentile among its peer group of 21,974 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (8)

microsoftpatch availablevia msrc
Product: 19464-16823Fixed in: 3.4.0-1
microsoftpatch availablevia msrc
Product: cbl2 python-ldap 3.4.0-1 on CBL Mariner 2.0Fixed in: 3.4.0-1
pippatch availablevia ghsa
Product: python-ldapFixed in: 3.4.0
redhatno patchvia redhat_api
Product: Red Hat Quay 3Fixed in: quay/quay-rhel8
redhatend of lifevia redhat_api
Product: Red Hat Ansible Automation Platform 1.2Fixed in: python-ldap
redhatend of lifevia redhat_api
Product: Red Hat Ansible Tower 3Fixed in: python-ldap
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: python-ldap
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: python-ldap

Vendor Advisories (3)

pipGHSA-qfr5-wjpw-q4c4medium

Denial of Service in python-ldap

Jun 19, 2022
microsoft2022-Jun/CVE-2021-46823Moderate

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.

Jun 14, 2022
redhatCVE-2021-46823Moderate

python-ldap: Regular expression denial of service in LDAP schema parser

Jan 18, 2022

References

exchange.xforce.ibmcloud.com / vulnerabilities/221507
Third Party AdvisoryVDB Entry
github.com / python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm
Third Party Advisory