SSRF in Dahlia Fedify

CVE-2025-23221

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:L.

EPSS exploit prediction

EPSS: 0.006 (46.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-23221: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

  • Dahlia Fedify — versions < 1.0.14, >= 1.1.0, < 1.1.11, >= 1.2.0, < 1.2.11

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-23221?
CVE-2025-23221 is a medium-severity vulnerability in Dahlia Fedify, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.4/10. Published 2025-01-20.
How severe is CVE-2025-23221?
Medium severity. CVSS v3 base score is 5.4 out of 10.