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.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-770"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/54xxx/CVE-2025-54879.json"
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.1.5"
},
{
"fixed": "4.2.24"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.3.0"
},
{
"fixed": "4.3.11"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.4.0"
},
{
"fixed": "4.4.3"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "e2592419d93fb41be03c2f3ff6a122fecb0e0952"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v4.4.3",
"range": [
{
"fixed": "5478ef9b32be0c7ac8f86330760485a7531d218a"
}
],
"source": "REFERENCES_TAG"
}
]
}