Description
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Prior to versions 1.6.13, 1.7.14, 1.8.15, and 1.9.2, a Regular Expression Denial of Service (ReDoS) vulnerability exists in Fedify's document loader. The HTML parsing regex at packages/fedify/src/runtime/docloader.ts:259 contains nested quantifiers that cause catastrophic backtracking when processing maliciously crafted HTML responses. This issue has been patched in versions 1.6.13, 1.7.14, 1.8.15, and 1.9.2.
Affected products
fedify: fedify
References7
- github.com/fedify-dev/fedify/security/advisories/GHSA-rchf-xwx2… ExploitMitigationVendor Advisory
- github.com/fedify-dev/fedify/commit/2bdcb24d7d6d5886e0214ed504b… Patch
- github.com/fedify-dev/fedify/commit/bf2f0783634efed2663d1b187dc… Patch
- github.com/fedify-dev/fedify/releases/tag/1.6.13 ProductRelease Notes
- github.com/fedify-dev/fedify/releases/tag/1.7.14 ProductRelease Notes
- github.com/fedify-dev/fedify/releases/tag/1.8.15 ProductRelease Notes
- github.com/fedify-dev/fedify/releases/tag/1.9.2 ProductRelease 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: 47 · as of 11 November 2026
- CWE
- CWE-1333
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.