{"id":"CVE-2025-54879","aliases":["BIT-mastodon-2025-54879","EUVD-2025-23661","GHSA-84ch-6436-c7mg"],"status":"published","title":"Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails","description":"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.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00613,"percentile":0.4965,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-770"],"published":"2025-08-05T23:39:59Z","modified":"2026-10-28T02:30:28Z","fixes":[{"ecosystem":"Bitnami","package":"mastodon","fixed_in":["4.2.24","4.3.11","4.4.3"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"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"}]}]}],"products":[{"vendor":"joinmastodon","product":"mastodon"},{"vendor":"mastodon","product":"mastodon"}],"references":[{"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-84ch-6436-c7mg","tags":["x_refsource_CONFIRM","exploit","Third Party Advisory","advisory"]},{"url":"https://github.com/mastodon/mastodon/commit/e2592419d93fb41be03c2f3ff6a122fecb0e0952","tags":["x_refsource_MISC","Patch","fix"]},{"url":"https://github.com/mastodon/mastodon/releases/tag/v4.4.3","tags":["x_refsource_MISC","Release Notes","article","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-54879","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/54xxx/CVE-2025-54879.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2025-54879","title":"Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails","description":"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.","status":"published","published":"2025-08-05T23:39:59.13Z","modified":"2025-08-06T20:32:56.74Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:32:27.603809Z"}],"euvd":[{"id":"EUVD-2025-23661","description":"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.","status":"published","published":"2025-08-05T23:39:59Z","modified":"2025-08-06T20:32:56Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-02T20:32:00.279926Z"}],"nvd":[{"id":"CVE-2025-54879","description":"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.","status":"published","published":"2025-08-06T00:15:31.88Z","modified":"2026-06-17T09:40:51.323Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:11:22.319351Z"}],"osv":[{"id":"CVE-2025-54879","title":"Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails","description":"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.","status":"published","published":"2025-08-05T23:39:59.13Z","modified":"2026-10-28T02:30:28.40906292Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:44:50.863921Z"},{"id":"BIT-mastodon-2025-54879","title":"Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails","description":"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.","status":"published","published":"2025-08-08T05:54:51.134Z","modified":"2026-09-08T08:48:13.237625341Z","updated_at":"2026-11-02T15:28:32.645004Z"}]}}