CVE-2025-23221

Fedify has an Infinite loop and Blind SSRF found inside the Webfinger mechanism

MEDIUM
5.4
CVSS Score
Published: January 20, 2025 at 04:49 PM UTC
Updated: June 17, 2026 at 08:52 AM UTC
1 product affected across 1 vendorFedify

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Severity
MEDIUM5.4
Exploit prediction
EPSS 0.6%
SSVC
PoC

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.0.14v < 1.1.11v < 1.2.11v < 1.3.4
Affected range stops below 1.0.14, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.1.11, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.2.11, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.3.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.4MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
LOW
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-835CWE-918

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