Vulnerability Description
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. In versions below 1.3.20, 1.4.0-dev.585 through 1.4.12, 1.5.0-dev.636 through 1.5.4, 1.6.0-dev.754 through 1.6.7, 1.7.0-pr.251.885 through 1.7.8 and 1.8.0-dev.909 through 1.8.4, an authentication bypass vulnerability allows any unauthenticated attacker to impersonate any ActivityPub actor by sending forged activities signed with their own keys. Activities are processed before verifying the signing key belongs to the claimed actor, enabling complete actor impersonation across all Fedify instances. This is fixed in versions 1.3.20, 1.4.13, 1.5.5, 1.6.8, 1.7.9 and 1.8.5.
Related Weaknesses (CWE)
References
- https://github.com/fedify-dev/fedify/commit/14a2f8c6d2c3cbc00c3170a86ad3b7b8555c
- https://github.com/fedify-dev/fedify/security/advisories/GHSA-6jcc-xgcr-q3h4
FAQ
What is CVE-2025-54888?
CVE-2025-54888 is a documented vulnerability. Fedify is a TypeScript library for building federated server apps powered by ActivityPub. In versions below 1.3.20, 1.4.0-dev.585 through 1.4.12, 1.5.0-dev.636 through 1.5.4, 1.6.0-dev.754 through 1.6...
How severe is CVE-2025-54888?
CVSS scoring is not yet available for CVE-2025-54888. Check NVD for updates.
Is there a patch for CVE-2025-54888?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.