PT-2026-69985 · Mastodon · Mastodon

CVE-2026-72916

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Published

2026-08-10

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Updated

2026-08-17

CVSS v4.0

6.3

Medium

VectorAV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:L/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
Name of the Vulnerable Software and Affected Versions Mastodon versions prior to 4.4.21 Mastodon versions prior to 4.5.14 Mastodon versions prior to 4.6.4 Mastodon versions prior to 4.7.0-beta.1
Description A Server-Side Request Forgery (SSRF) protection bypass exists in the PrivateAddressCheck.private address? function within app/lib/private address check.rb. While the system normalized IPv4-mapped IPv6 addresses, it failed to recognize IPv4-compatible IPv6 addresses using IPAddr#ipv4 compat?. An attacker could use an address from this omitted range to bypass the ALLOWED PRIVATE ADDRESSES protection, forcing the server to send HTTP requests to loopback interfaces. This could allow unauthorized access to private resources and services, provided the underlying system supports the obsolete IPv4-compatible IPv6 mechanism.
Recommendations Update to version 4.4.21 Update to version 4.5.14 Update to version 4.6.4 Update to version 4.7.0-beta.1

Exploit

Fix

SSRF

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Weakness Enumeration

Related Identifiers

BIT-MASTODON-2026-72916
CVE-2026-72916
GHSA-VWHJ-3G83-V276

Affected Products

Mastodon