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High · 8.6 Public exploit CVE-2026-50131 EUVD-2026-36132GHSA-xw9q-2mv6-9fr8

Fedify has an incomplete SSRF mitigation after GHSA-p9cg-vqcc-grcx: validatePublicUrl allows special-use IPv4 ranges

Published Jun 10, 2026 · Updated Jun 11, 2026 · Assigned by GitHub_M

Vendor: fedify-dev Product: fedify Product: vocab-runtime Package: @fedify/fedify Package: @fedify/vocab-runtime Ecosystem: npm

Description

Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Fedify previously addressed SSRF/internal network access in GHSA-p9cg-vqcc-grcx by adding public URL validation before runtime document and media fetching. However, the IPv4 validation logic present starting in version 0.11.2 and prior to versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 appears incomplete. The `validatePublicUrl()` protection relies on `isValidPublicIPv4Address()` to reject non-public IPv4 destinations. The function blocks common private and local ranges such as `10.0.0.0/8`, `127.0.0.0/8`, `169.254.0.0/16`, `172.16.0.0/12`, and `192.168.0.0/16`, but it still treats several special-use, reserved, multicast, benchmarking, and carrier-grade NAT IPv4 ranges as valid public destinations. Because this validation is used as an SSRF defense before outbound fetches, this appears to be an incomplete mitigation or bypass class for the previous SSRF issue. Versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 contain an updated patch.

Affected products

VendorProductAffectedFixed
fedify-dev fedify >= 0.11.2, < 1.9.12, >= 1.10.0, < 1.10.11, >= 2.0.0, < 2.0.19, >= 2.1.0, < 2.1.15, >= 2.2.0, < 2.2.4 —
fedify-dev vocab-runtime < 2.0.19, >= 2.1.0, < 2.1.15, >= 2.2.0, < 2.2.4 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Affected packages

EcosystemPackageAffectedFixedRecord
npm @fedify/fedify >= 0.11.2, < 1.9.12 1.9.12 GHSA-xw9q-2mv6-9fr8
npm @fedify/fedify >= 1.10.0, < 1.10.11 1.10.11 GHSA-xw9q-2mv6-9fr8
npm @fedify/fedify >= 2.0.0, < 2.0.19 2.0.19 GHSA-xw9q-2mv6-9fr8
npm @fedify/fedify >= 2.1.0, < 2.1.15 2.1.15 GHSA-xw9q-2mv6-9fr8
npm @fedify/fedify >= 2.2.0, < 2.2.4 2.2.4 GHSA-xw9q-2mv6-9fr8
npm @fedify/vocab-runtime < 2.0.19 2.0.19 GHSA-xw9q-2mv6-9fr8
npm @fedify/vocab-runtime >= 2.1.0, < 2.1.15 2.1.15 GHSA-xw9q-2mv6-9fr8
npm @fedify/vocab-runtime >= 2.2.0, < 2.2.4 2.2.4 GHSA-xw9q-2mv6-9fr8

References