Vulnerability from bitnami_vulndb
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": [
{
"package": {
"ecosystem": "Bitnami",
"name": "mastodon",
"purl": "pkg:bitnami/mastodon"
},
"ranges": [
{
"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"
}
],
"type": "SEMVER"
}
],
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
],
"aliases": [
"CVE-2025-54879"
],
"database_specific": {
"cpes": [
"cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*"
],
"severity": "High"
},
"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\u0027s 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.",
"id": "BIT-mastodon-2025-54879",
"modified": "2025-08-27T09:06:48.117Z",
"published": "2025-08-08T05:54:51.134Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/mastodon/mastodon/commit/e2592419d93fb41be03c2f3ff6a122fecb0e0952"
},
{
"type": "WEB",
"url": "https://github.com/mastodon/mastodon/releases/tag/v4.4.3"
},
{
"type": "WEB",
"url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-84ch-6436-c7mg"
},
{
"type": "WEB",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-54879"
}
],
"schema_version": "1.6.2",
"summary": "Mastodon e\u2011mail throttle misconfiguration allows unlimited email confirmations against unconfirmed emails"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.