CVE-2026-46348
Mastodon: SSRF Bypass via IPv6 Unspecified Address (::)
EPSS 0.34%
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.
How to fix CVE-2026-46348
To remediate CVE-2026-46348, upgrade the affected package to a fixed version below.
- —upgrade to 4.5.10 or later
Is CVE-2026-46348 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 4.5.0, < 4.5.10
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |