CVE-2024-23832: Joinmastodon Mastodon

Critical severity, CVSS 9.8. EPSS: 2.5% chance of exploitation in the next 30 days.

Mastodon is a free, open-source social network server based on ActivityPub Mastodon allows configuration of LDAP for authentication. Due to insufficient origin validation in all Mastodon, attackers can impersonate and take over any remote account. Every Mastodon version prior to 3.5.17 is vulnerable, as well as 4.0.x versions prior to 4.0.13, 4.1.x version prior to 4.1.13, and 4.2.x versions prior to 4.2.5.

Affected products

• Joinmastodon Mastodon: before 3.5.17 (fixed in 3.5.17); from 4.0.0, before 4.0.13 (fixed in 4.0.13); from 4.1.0, before 4.1.13 (fixed in 4.1.13); from 4.2.0, before 4.2.5 (fixed in 4.2.5)

Published 2024-02-01. Last modified 2026-06-17.