Mastodon's blind LDAP injection in login allows the attacker to leak arbitrary attributes from LDAP database
Priority HIGH 67CWE-90Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01279 70th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed mastodon (mastodon): 3.5.8, 4.0.4, 4.1.2
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| mastodon | mastodon | 2.5.0 to before 3.5.8; 4.0.0 to before 4.0.4; 4.1.0 to before 4.1.2 | 3.5.8, 4.0.4, 4.1.2 | Patch available | CNA |
- mastodon Vendormastodon Affected 2.5.0 to before 3.5.8; 4.0.0 to before 4.0.4; 4.1.0 to before 4.1.2 Fixed in 3.5.8, 4.0.4, 4.1.2 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:* | 2.5.0 to before 3.5.8; 4.0.0 to before 4.0.4; 4.1.0 to before 4.1.2 | Vulnerable | mastodon |
- cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:* Versions 2.5.0 to before 3.5.8; 4.0.0 to before 4.0.4; 4.1.0 to before 4.1.2 Vulnerable ·mastodon
Remediation
- Fix · CNA mastodon (mastodon) Fixed in 3.5.8, 4.0.4, 4.1.2
Timeline
- 2026-10-02 Threatist record created from CVE-2023-28853
References
Other 6
- https://github.com/mastodon/mastodon/blob/94cbd808b5b3e7999c7e77dc724b7e8c9dd2bdec/app/models/concerns/ldap_authenticable.rb#L7-L14
- https://github.com/mastodon/mastodon/blob/94cbd808b5b3e7999c7e77dc724b7e8c9dd2bdec/config/initializers/devise.rb#L398-L414
- https://github.com/mastodon/mastodon/releases/tag/v3.5.8
- https://github.com/mastodon/mastodon/releases/tag/v4.0.4
- https://github.com/mastodon/mastodon/releases/tag/v4.1.2
- http://www.openwall.com/lists/oss-security/2023/07/06/6
More Mastodon vulnerabilities
- TI-2022-02004 Improper Restriction of Excessive Authentication Attempts in mastodon/mastodon CVSS 3.1CRITICAL 9.8
- TI-2025-34613 Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails CVSS 3.1HIGH 7.5
- TI-2022-22936 Mastodon through 4.0.2 allows attackers to cause a denial of service (large Sidekiq pull… CVSS 3.1HIGH 7.5
- TI-2023-18301 Mastodon vulnerable to arbitrary file creation through media attachments CVSS 3.1CRITICAL 10.0
- TI-2024-16846 External OpenID Connect Account Takeover by E-Mail Change in mastodon CVSS 3.1HIGH 7.4
- TI-2024-15826 Mastodon Remote user impersonation and takeover CVSS 3.1CRITICAL 9.8
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences