CVE-2026-46348

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, the list of disallowed IP address ranges was lacking an IP address range that can be used to reach local IP addresses. An attacker can use an IP address in the affected range to make Mastodon perform HTTP requests against loopback interfaces, potentially allowing access to otherwise private resources and services. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23.

Score
CVSS 4.0 8.7 High
Status
Deferred - security-advisories@github.com
Published
2026-06-24
Last modified
2026-06-25
Weaknesses
CWE-918

Affected products

References