CVE-2024-25618

Mastodon is a free, open-source social network server based on ActivityPub. Mastodon allows new identities from configured authentication providers (CAS, SAML, OIDC) to attach to existing local users with the same e-mail address. This results in a possible account takeover if the authentication provider allows changing the e-mail address or multiple authentication providers are configured. When a user logs in through an external authentication provider for the first time, Mastodon checks the e-mail address passed by the provider to find an existing account. However, using the e-mail address alone means that if the authentication provider allows changing the e-mail address of an account, the Mastodon account can immediately be hijacked. All users logging in through external authentication providers are affected. The severity is medium, as it also requires the external authentication provider to misbehave. However, some well-known OIDC providers (like Microsoft Azure) make it very easy to accidentally allow unverified e-mail changes. Moreover, OpenID Connect also allows dynamic client registration. This issue has been addressed in versions 4.2.6, 4.1.14, 4.0.14, and 3.5.18. Users are advised to upgrade. There are no known workarounds for this vulnerability.

• CWE-287
• CWE-306

• https://github.com/mastodon/mastodon/commit/b31af34c9716338e4a32a62cc812d1ca59e88d15Patch
• https://github.com/mastodon/mastodon/security/advisories/GHSA-vm39-j3vx-pch3Exploit, Vendor Advisory
• https://github.com/mastodon/mastodon/commit/b31af34c9716338e4a32a62cc812d1ca59e88d15Patch
• https://github.com/mastodon/mastodon/security/advisories/GHSA-vm39-j3vx-pch3Exploit, Vendor Advisory

Published

Feb 14, 2024

Last Modified

Jun 17, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2024-25612Authenticated command injection vulnerabilities exist in the…7.2
• CVE-2024-25613Authenticated command injection vulnerabilities exist in the…7.2
• CVE-2024-25614There is an arbitrary file deletion vulnerability in the CLI…9.1
• CVE-2024-25615 An unauthenticated Denial-of-Service (DoS) vulnerability ex…5.3
• CVE-2024-25616Aruba has identified certain configurations of ArubaOS that …3.7
• CVE-2024-25617Squid is an open source caching proxy for the Web supporting…7.5
• CVE-2024-25619Mastodon is a free, open-source social network server based …4.3
• CVE-2024-2562A vulnerability, which was classified as critical, was found…9.8
• CVE-2024-25620Helm is a tool for managing Charts. Charts are packages of p…6.4
• CVE-2024-25621containerd is an open-source container runtime. Versions 0.1…7.8
• CVE-2024-25622h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and …4.3
• CVE-2024-25623Mastodon is a free, open-source social network server based …7.7