# CVE-2025-68475: 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.

Source: https://junglewise.ai/threats/cve-2025-68475-fedify-redos-vulnerability-in-html-parsing-regex  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-12-22. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2025-68475 · Severity: high · CVSS 7.5 · Published 2025-12-22

Fedify is a TypeScript library for building federated applications that follow ActivityPub standards. The library contains a regular expression denial of service (ReDoS) vulnerability in its HTML parser that can be triggered when fetching actor profiles from untrusted federated servers. An attacker can serve a small, specially crafted HTML response (~170 bytes) that causes Fedify's Node.js event loop to block for 14+ seconds, effectively disabling the service and preventing legitimate requests from being processed.

Technologies: [Fedify](https://junglewise.ai/threats/technologies/fedify). Vendors: [Fedify](https://junglewise.ai/threats/vendors/fedify).

## Quick answers

**Is CVE-2025-68475 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-68475 being exploited in the wild.

**How severe is CVE-2025-68475?** High severity, with a CVSS score of 7.5, published 22 December 2025.

**Which products and versions are affected?** Fedify <=1.9.1.

**Is there a fix for CVE-2025-68475?** A patch was published on 2025-12-22: Patched versions 1.6.13, 1.7.14, 1.8.15, 1.9.2 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-68475 attacked?** It is attacked over the network.

**Am I affected by CVE-2025-68475?** Check whether you run Fedify at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in packages/fedify/src/runtime/docloader.ts:259, where a regular expression with nested quantifiers and alternation is used to parse HTML attributes: `/&lt;(a|link)((\s+[a-z][a-z:_-]*=("[^"]*"|'[^']*'|[^\s&gt;]+))+)\s*\/?&gt;/ig`. The nested quantifier pattern (`((...)+)+`) combined with alternation creates exponential backtracking when the regex engine fails to match incomplete HTML tags. The vulnerability is remotely exploitable without authentication because Fedify fetches profiles from untrusted federated servers, and there are no response size limits or default timeouts enforced. An attacker can block the event loop by sending a malicious payload, causing a denial of service that degrades or disables the application. Patched versions (1.6.13, 1.7.14, 1.8.15, 1.9.2) are available.

## Affected products

- Fedify Fedify <=1.9.1

## Identifiers

- CVE-2025-68475
- GHSA-rchf-xwx2-hm93

## Timeline

- 2025-12-22: disclosed: Vulnerability published via GHSA-rchf-xwx2-hm93
- 2025-12-22: patched: Patched versions 1.6.13, 1.7.14, 1.8.15, 1.9.2 released

## References

- [https://github.com/fedify-dev/fedify/security/advisories/GHSA-rchf-xwx2-hm93](https://github.com/fedify-dev/fedify/security/advisories/GHSA-rchf-xwx2-hm93)

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- [Fedify authentication bypass in ActivityPub inbox handler](https://junglewise.ai/threats/cve-2025-54888-fedify-authentication-bypass-in-activitypub-inbox-handler)