Description
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Prior to 1.9.6, 1.10.5, 2.0.8, and 2.1.1, @fedify/fedify follows HTTP redirects recursively in its remote document loader and authenticated document loader without enforcing a maximum redirect count or visited-URL loop detection. An attacker who controls a remote ActivityPub key or actor URL can force a server using Fedify to make repeated outbound requests from a single inbound request, leading to resource consumption and denial of service. This vulnerability is fixed in 1.9.6, 1.10.5, 2.0.8, and 2.1.1.
Affected products
fedify: fedify\/fedify; fedify: fedify\/vocab-runtime
References6
- github.com/fedify-dev/fedify/security/advisories/GHSA-gm9m-gwc4… ExploitVendor Advisory
- github.com/fedify-dev/fedify/security/advisories/GHSA-gm9m-gwc4… ExploitVendor Advisory
- github.com/fedify-dev/fedify/releases/tag/1.10.5 Release Notes
- github.com/fedify-dev/fedify/releases/tag/1.9.6 Release Notes
- github.com/fedify-dev/fedify/releases/tag/2.0.8 Release Notes
- github.com/fedify-dev/fedify/releases/tag/2.1.1 Release Notes
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 48 · as of 12 November 2026
- CWE
- CWE-400CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.