Description
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.5.8, 4.4.15, and 4.3.21, an unauthenticated Open Redirect vulnerability (CWE-601) exists in the `/web/*` route due to improper handling of URL-encoded path segments. An attacker can craft a specially encoded URL that causes the application to redirect users to an arbitrary external domain, enabling phishing attacks and potential OAuth credential theft. The issue occurs because URL-encoded slashes (`%2F`) bypass Rails path normalization and are interpreted as host-relative redirects. Versions 4.5.8, 4.4.15, and 4.3.21 patch the issue.
CVSS 4.3EPSS 0.515%Risque 0.45
Voir la source- Publication
- 2026-03-27 20:16:34
- Versions concernées
- <4.3.21, <4.4.15, <4.5.8
- Type
- Core software
- Vecteur
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N