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.
Metrics
Affected Vendors & Products
References
History
Tue, 26 Aug 2025 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:* |
Thu, 07 Aug 2025 07:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Joinmastodon
Joinmastodon mastodon |
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| Vendors & Products |
Joinmastodon
Joinmastodon mastodon |
Wed, 06 Aug 2025 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Tue, 05 Aug 2025 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Mastodon e‑mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails | |
| Weaknesses | CWE-770 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2025-08-05T23:39:59.130Z
Updated: 2025-08-06T20:32:56.740Z
Reserved: 2025-07-31T17:23:33.475Z
Link: CVE-2025-54879
Updated: 2025-08-06T16:14:05.680Z
Status : Analyzed
Published: 2025-08-06T00:15:31.880
Modified: 2025-08-26T13:57:17.110
Link: CVE-2025-54879
No data.