fedify up to 1.8.4 improper authentication

Summaryinfo

A vulnerability categorized as critical has been discovered in fedify up to 1.8.4. This impacts an unknown function. Executing a manipulation can lead to improper authentication. This vulnerability is handled as CVE-2025-54888. The attack can be executed remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in fedify up to 1.8.4 and classified as critical. This vulnerability affects an unknown functionality. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability was named CVE-2025-54888 since 07/31/2025. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available.

Upgrading to version 1.3.20, 1.4.13, 1.5.5, 1.6.8, 1.7.9 or 1.8.5 eliminates this vulnerability. Applying the patch 226d9b84dbec52172a70138bba8861454afde42b is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-24039). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• fedify

Version

• 1.3.0
• 1.3.1
• 1.3.2
• 1.3.3
• 1.3.4
• 1.3.5
• 1.3.6
• 1.3.7
• 1.3.8
• 1.3.9
• 1.3.10
• 1.3.11
• 1.3.12
• 1.3.13
• 1.3.14
• 1.3.15
• 1.3.16
• 1.3.17
• 1.3.18
• 1.3.19
• 1.4.0
• 1.4.1
• 1.4.2
• 1.4.3
• 1.4.4
• 1.4.5
• 1.4.6
• 1.4.7
• 1.4.8
• 1.4.9
• 1.4.10
• 1.4.11
• 1.4.12
• 1.5.0
• 1.5.1
• 1.5.2
• 1.5.3
• 1.5.4
• 1.6.0
• 1.6.1
• 1.6.2
• 1.6.3
• 1.6.4
• 1.6.5
• 1.6.6
• 1.6.7
• 1.7.0
• 1.7.1
• 1.7.2
• 1.7.3
• 1.7.4
• 1.7.5
• 1.7.6
• 1.7.7
• 1.7.8
• 1.8.0
• 1.8.1
• 1.8.2
• 1.8.3
• 1.8.4

License

• open-source

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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