CVE-2025-54888
August 09, 2025
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.
Affected Packages
@fedify/fedify (NPM):
Affected version(s) >=1.7.0-pr.251.885 <1.7.9Fix Suggestion:
Update to version 1.7.9@fedify/fedify (NPM):
Affected version(s) >=1.6.0-dev.754 <1.6.8Fix Suggestion:
Update to version 1.6.8@fedify/fedify (NPM):
Affected version(s) >=1.4.0-dev.585 <1.4.13Fix Suggestion:
Update to version 1.4.13@fedify/fedify (NPM):
Affected version(s) >=0.5.0 <1.3.20Fix Suggestion:
Update to version 1.3.20@fedify/fedify (NPM):
Affected version(s) >=1.8.0-dev.909 <1.8.5Fix Suggestion:
Update to version 1.8.5@fedify/fedify (NPM):
Affected version(s) >=1.5.0-dev.636 <1.5.5Fix Suggestion:
Update to version 1.5.5Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
EPSS
Base Score:
0.10
