What is the CVSS score of CVE-2025-23221?

CVE-2025-23221 has a CVSS 3.1 base score of 5.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L. EPSS exploitation probability: 0.1%.

Which versions of Fedify are affected by CVE-2025-23221?

Organizations using Fedify should be aware of moderate risk from CVE-2025-23221 rated CVSS 5.4. Exploitation could compromise the security of affected deployments.. A patch is available.

How to fix or mitigate CVE-2025-23221?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Fedify CVE-2025-23221

MEDIUM

Loop with Unreachable Exit Condition (Infinite Loop) (CWE-835)

2025-01-20 security-advisories@github.com

SSRF Denial Of Service

5.4

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

5.4 MEDIUM

AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

None

Availability

Low

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 28, 2026 - 18:04 vuln.today

CVE Published

Jan 20, 2025 - 17:15 nvd

MEDIUM 5.4

DescriptionGitHub Advisory

Fedify is a TypeScript library for building federated server apps powered by ActivityPub and other standards. This vulnerability allows a user to maneuver the Webfinger mechanism to perform a GET request to any internal resource on any Host, Port, URL combination regardless of present security mechanisms, and forcing the victim’s server into an infinite loop causing Denial of Service. Moreover, this issue can also be maneuvered into performing a Blind SSRF attack. This vulnerability is fixed in 1.0.14, 1.1.11, 1.2.11, and 1.3.4.

AnalysisAI

Fedify is a TypeScript library for building federated server apps powered by ActivityPub and other standards. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-835. Fedify is a TypeScript library for building federated server apps powered by ActivityPub and other standards. This vulnerability allows a user to maneuver the Webfinger mechanism to perform a GET request to any internal resource on any Host, Port, URL combination regardless of present security mechanisms, and forcing the victim’s server into an infinite loop causing Denial of Service. Moreover, this issue can also be maneuvered into performing a Blind SSRF attack. This vulnerability is fixed in 1.0.14, 1.1.11, 1.2.11, and 1.3.4.

Affected ProductsAI

See vendor advisory for affected versions.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.