{"id":"BIT-mastodon-2025-54879","summary":"Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails","details":"Mastodon is a free, open-source social network server based on ActivityPub Mastodon which facilitates LDAP configuration for authentication. In versions 3.1.5 through 4.2.24, 4.3.0 through 4.3.11 and 4.4.0 through 4.4.3, Mastodon's rate-limiting system has a critical configuration error where the email-based throttle for confirmation emails incorrectly checks the password reset path instead of the confirmation path, effectively disabling per-email limits for confirmation requests. This allows attackers to bypass rate limits by rotating IP addresses and send unlimited confirmation emails to any email address, as only a weak IP-based throttle (25 requests per 5 minutes) remains active. The vulnerability enables denial-of-service attacks that can overwhelm mail queues and facilitate user harassment through confirmation email spam. This is fixed in versions 4.2.24, 4.3.11 and 4.4.3.","aliases":["CVE-2025-54879","GHSA-84ch-6436-c7mg"],"modified":"2026-09-08T08:48:13.237625341Z","published":"2025-08-08T05:54:51.134Z","database_specific":{"severity":"High","cpes":["cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*"]},"references":[{"type":"FIX","url":"https://github.com/mastodon/mastodon/commit/e2592419d93fb41be03c2f3ff6a122fecb0e0952"},{"type":"ARTICLE","url":"https://github.com/mastodon/mastodon/releases/tag/v4.4.3"},{"type":"ADVISORY","url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-84ch-6436-c7mg"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-54879"}],"affected":[{"package":{"name":"mastodon","ecosystem":"Bitnami","purl":"pkg:bitnami/mastodon"},"ranges":[{"type":"SEMVER","events":[{"introduced":"3.1.5"},{"fixed":"4.2.24"},{"introduced":"4.3.0"},{"fixed":"4.3.11"},{"introduced":"4.4.0"},{"fixed":"4.4.3"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/mastodon/BIT-mastodon-2025-54879.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}],"schema_version":"1.9.0"}