CVE-2026-50131
Published: Wed, 10 Jun 2026 22:17
Summary
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 validatio
Details
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.
Are YOU affected by CVE-2026-50131?
5-second check on your actual server. Reads /etc/os-release, uname -r, and dpkg-query; matches against the live USN + Debian Security Tracker feeds; tells you whether CVE-2026-50131 (and any other live CVE) applies. Anonymous, no signup.
curl https://mindsparkstack.com/scan.sh | bash
References
StackPatch runs this match against YOUR installed packages every hour
Free (3 servers) / from $9/mo (14-day free trial) / Solo $9/mo / Pro $29/mo / Team $79/mo. Indie pricing.