---
id: CVE-2020-26214
aliases:
  - GHSA-5hmm-x8q8-w5jh
  - PYSEC-2020-159
title: LDAP authentication bypass with empty password
summary: LDAP authentication bypass with empty password
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
vendor: alerta-server
product: alerta-server
ecosystem: pip
affected:
  - 'alerta-server >= 8.0.0, < 8.1.0'
  - alerta-server < 7.5.7
patched:
  - alerta-server 8.1.0
  - alerta-server 7.5.7
published: '2020-11-06'
updated: '2026-07-08'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-5hmm-x8q8-w5jh'
references:
  - url: 'https://github.com/alerta/alerta/security/advisories/GHSA-5hmm-x8q8-w5jh'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2020-26214'
  - url: 'https://github.com/alerta/alerta/issues/1277'
  - url: 'https://github.com/alerta/alerta/pull/1345'
  - url: >-
      https://github.com/alerta/alerta/commit/2bfa31779a4c9df2fa68fa4d0c5c909698c5ef65
  - url: 'https://github.com/alerta/alerta'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/alerta-server/PYSEC-2020-159.yaml
  - url: 'https://pypi.org/project/alerta-server/8.1.0'
  - url: 'https://tools.ietf.org/html/rfc4513#section-5.1.2'
tags:
  - osv
  - pip
  - exploit-available
epss: 0.65933
epssPercentile: 0.99249
ingestedAt: '2026-07-08T18:25:46.005Z'
exploits:
  nuclei:
    - CVE-2020-26214
  checkedAt: '2026-09-26T09:05:25.930Z'
exploitAvailable: true
---

## Overview

### Impact
Users may be able to bypass LDAP authentication if they provide an empty password when Alerta server is configure to use LDAP as the authorization provider.

Only deployments where LDAP servers are configured to allow unauthenticated binds (eg. default on Active Directory) are affected.

### Patches
A fix has been implemented that returns HTTP 401 Unauthorized response for any authentication attempts where the password field is empty. See https://github.com/alerta/alerta/pull/1345

### Workarounds
LDAP administrators can disallow unauthenticated bind requests by clients.

### References
https://tools.ietf.org/html/rfc4513#section-5.1.2
https://pypi.org/project/alerta-server/8.1.0/

### For more information
If you have any questions or comments about this advisory:
* Add a comment to the issue [#1277](https://github.com/alerta/alerta/issues/1277)
* Email us at [admin@alerta.dev](mailto:admin@alerta.dev)

## Affected packages

- `alerta-server >= 8.0.0, < 8.1.0`
- `alerta-server < 7.5.7`

## Remediation

Upgrade to a patched release:

- `alerta-server 8.1.0`
- `alerta-server 7.5.7`