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CVE PROGRAM SOURCE RECORD8.7 High

CVE-2026-46348

Mastodon: SSRF Bypass via IPv6 Unspecified Address (::)

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

mastodon mastodon

  • >= 4.5.0-beta.1, < 4.5.10affected

References