# CVE-2023-28853

## Summary

- **CVE ID:** CVE-2023-28853
- **Severity:** HIGH
- **CVSS Score:** 7.7 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N)
- **CWE:** CWE-90
- **Published:** Apr 4, 2023
- **Last Modified:** Mar 13, 2026

## Description

Mastodon is a free, open-source social network server based on ActivityPub Mastodon allows configuration of LDAP for authentication. Starting in version 2.5.0 and prior to versions 3.5.8, 4.0.4, and 4.1.2, the LDAP query made during login is insecure and the attacker can perform LDAP injection attack to leak arbitrary attributes from LDAP database. This issue is fixed in versions 3.5.8, 4.0.4, and 4.1.2.

## Affected Products

- mastodon — mastodon (>= 2.5.0, < 3.5.8)
- mastodon — mastodon (>= 4.0.0, < 4.0.4)
- mastodon — mastodon (>= 4.1.0, < 4.1.2)

## References

- [CNA](https://github.com/mastodon/mastodon/security/advisories/GHSA-38g9-pfm9-gfqv)
- [CNA](https://github.com/mastodon/mastodon/pull/24379)
- [CNA](https://github.com/mastodon/mastodon/blob/94cbd808b5b3e7999c7e77dc724b7e8c9dd2bdec/app/models/concerns/ldap_authenticable.rb#L7-L14)
- [CNA](https://github.com/mastodon/mastodon/blob/94cbd808b5b3e7999c7e77dc724b7e8c9dd2bdec/config/initializers/devise.rb#L398-L414)
- [CNA](https://github.com/mastodon/mastodon/releases/tag/v3.5.8)
- [CNA](https://github.com/mastodon/mastodon/releases/tag/v4.0.4)
- [CNA](https://github.com/mastodon/mastodon/releases/tag/v4.1.2)
- [CNA](http://www.openwall.com/lists/oss-security/2023/07/06/6)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.37%
- **EPSS Percentile:** 58.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._