Summary
@fedify/fedify has Improper Authentication and Incorrect Authorization
Impact
Type: Authentication Bypass / Actor Impersonation
Who is impacted: All Fedify instances and their users
Consequences: Allows complete impersonation of any ActivityPub actor, enabling:
- Sending fake posts/messages as any user
- Creating/removing follows as any user
- Boosting/sharing content as any user
- Complete compromise of federation trust model
The vulnerability affects all Fedify instances but does not propagate to other ActivityPub implementations (Mastodon, etc.) which properly validate before processing.
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
@fedify/fedify to 1.3.20 or later; @fedify/fedify to 1.4.13 or later; @fedify/fedify to 1.5.5 or later; @fedify/fedify to 1.6.8 or later; @fedify/fedify to 1.7.9 or later; @fedify/fedify to 1.8.5 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2025-54888? CVE-2025-54888 is a high-severity improper authentication vulnerability in @fedify/fedify (npm), affecting versions < 1.3.20. It is fixed in 1.3.20, 1.4.13, 1.5.5, 1.6.8, 1.7.9, 1.8.5. The application does not adequately verify the identity of a user, device, or process before granting access.
- Which versions of @fedify/fedify are affected by CVE-2025-54888? @fedify/fedify (npm) versions < 1.3.20 is affected.
- Is there a fix for CVE-2025-54888? Yes. CVE-2025-54888 is fixed in 1.3.20, 1.4.13, 1.5.5, 1.6.8, 1.7.9, 1.8.5. Upgrade to this version or later.
- Is CVE-2025-54888 exploitable, and should I be worried? Whether CVE-2025-54888 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-54888 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-54888?
- Upgrade
@fedify/fedifyto 1.3.20 or later - Upgrade
@fedify/fedifyto 1.4.13 or later - Upgrade
@fedify/fedifyto 1.5.5 or later - Upgrade
@fedify/fedifyto 1.6.8 or later - Upgrade
@fedify/fedifyto 1.7.9 or later - Upgrade
@fedify/fedifyto 1.8.5 or later
- Upgrade