CVE-2025-54888
Published: 09 August 2025
Summary
CVE-2025-54888 is a high-severity Improper Authentication (CWE-287) vulnerability. Its CVSS base score is 8.7 (High).
Operationally, ranked at the 36.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-24039
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Session content review can reveal authentication bypasses or failures in session establishment.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.
Identity providers centralize and enforce authentication mechanisms, reducing improper authentication.
Enforces correct authorization checks during the identifier assignment process.
Personnel screening, identity verification, and access-agreement requirements support reliable authentication and reduce authentication bypass opportunities.
Decoy authentication surfaces detect bypass attempts and deflect real credential attacks through observable malicious interactions.
Periodic review and update of procedures reduces incorrect authorization implementations over time.
Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.