{"id":"CVE-2025-54879","state":"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.","publishedAt":"2025-08-05T23:39:59.130Z","updatedAt":"2025-08-06T20:32:56.740Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["mastodon mastodon"],"affected":[{"vendor":"mastodon","product":"mastodon","versions":[{"version":">= 3.1.5, < 4.2.24","status":"affected"},{"version":">= 4.3.0, < 4.3.11","status":"affected"},{"version":">= 4.4.0, < 4.4.3","status":"affected"}]}],"references":["https://github.com/mastodon/mastodon/security/advisories/GHSA-84ch-6436-c7mg","https://github.com/mastodon/mastodon/commit/e2592419d93fb41be03c2f3ff6a122fecb0e0952","https://github.com/mastodon/mastodon/releases/tag/v4.4.3"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:09:31.862Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/54xxx/CVE-2025-54879.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2025-54879","state":"PUBLISHED","datePublished":"2025-08-05T23:39:59.130Z","dateUpdated":"2025-08-06T20:32:56.740Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2025-07-31T17:23:33.475Z"},"containers":{"cna":{"title":"Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"mastodon","product":"mastodon","versions":[{"version":">= 3.1.5, < 4.2.24","status":"affected"},{"version":">= 4.3.0, < 4.3.11","status":"affected"},{"version":">= 4.4.0, < 4.4.3","status":"affected"}]}],"references":[{"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-84ch-6436-c7mg","name":"https://github.com/mastodon/mastodon/security/advisories/GHSA-84ch-6436-c7mg","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/mastodon/mastodon/commit/e2592419d93fb41be03c2f3ff6a122fecb0e0952","name":"https://github.com/mastodon/mastodon/commit/e2592419d93fb41be03c2f3ff6a122fecb0e0952","tags":["x_refsource_MISC"]},{"url":"https://github.com/mastodon/mastodon/releases/tag/v4.4.3","name":"https://github.com/mastodon/mastodon/releases/tag/v4.4.3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2025-08-05T23:39:59.130Z"},"source":{"advisory":"GHSA-84ch-6436-c7mg","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-84ch-6436-c7mg","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-08-06T20:32:42.219873Z","id":"CVE-2025-54879","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-08-06T20:32:56.740Z"}}]}}}