CVE-2026-46348 — Mastodon: SSRF Bypass via IPv6 Unspecified Address (::)
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 addre…
Published: 2026-06-24 · CVSS: 8.7 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7