CVE-2025-54888 - CVE House
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Status published High CVE-2025-54888

@fedify/fedify: Improper Authentication and Incorrect Authorization

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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

fedify
Vulnerable Versions:
< 1.3.20, >= 1.4.0-dev.585, < 1.4.13, >= 1.5.0-dev.636, < 1.5.5, >= 1.6.0-dev.754, < 1.6.8, >= 1.7.0-pr.251.885, < 1.7.9, >= 1.8.0-dev.909, < 1.8.5

Timeline

Official Publish: August 9th, 2025
Last Modified: February 4th, 2026
Added to House: July 22nd, 2026

CVSS Vectors

Weaknesses (CWE)