CVE-2025-54888
BaseFortify
Publication date: 2025-08-09
Last updated on: 2026-02-04
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| fedify | fedify | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
| CWE-287 | When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability in the Fedify TypeScript library allows an unauthenticated attacker to impersonate any ActivityPub actor by sending forged activities signed with their own keys. The system processes these activities before verifying that the signing key belongs to the claimed actor, enabling complete actor impersonation across all Fedify instances.
How can this vulnerability impact me? :
The vulnerability can allow attackers to impersonate any user or actor within Fedify-powered applications, potentially leading to unauthorized actions, misinformation, or abuse of trust within federated server apps using ActivityPub.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade Fedify to one of the fixed versions: 1.3.20, 1.4.13, 1.5.5, 1.6.8, 1.7.9, or 1.8.5. These versions contain the fix for the authentication bypass vulnerability that allows actor impersonation.