CVE-2025-54888

@fedify/fedify: Improper Authentication and Incorrect Authorization

Published Aug 9, 2025 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-24039 @fedify/fedify has Improper Authentication and Incorrect Authorization
Github GHSA Github GHSA GHSA-6jcc-xgcr-q3h4 @fedify/fedify has Improper Authentication and Incorrect Authorization
History
Type Values Removed Values Added
First Time appeared Fedify Project
Fedify Project fedify
Vendors & Products Fedify Project
Fedify Project fedify
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title @fedify/fedify: Improper Authentication and Incorrect Authorization
Weaknesses CWE-287
CWE-863
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Feb 4, 2026, 10:13 PM
Reserved
Jul 31, 2025, 5:23 PM
Status
Deferred
Published
Aug 9, 2025, 2:15 AM
Modified
Jun 17, 2026, 9:40 AM