CVE-2026-50131 Details
Description
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Fedify previously addressed SSRF/internal network access in GHSA-p9cg-vqcc-grcx by adding public URL validation before runtime document and media fetching. However, the IPv4 validation logic present starting in version 0.11.2 and prior to versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 appears incomplete. The `validatePublicUrl()` protection relies on `isValidPublicIPv4Address()` to reject non-public IPv4 destinations. The function blocks common private and local ranges such as `10.0.0.0/8`, `127.0.0.0/8`, `169.254.0.0/16`, `172.16.0.0/12`, and `192.168.0.0/16`, but it still treats several special-use, reserved, multicast, benchmarking, and carrier-grade NAT IPv4 ranges as valid public destinations. Because this validation is used as an SSRF defense before outbound fetches, this appears to be an incomplete mitigation or bypass class for the previous SSRF issue. Versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 contain an updated patch.
A vulnerability exists in the Fedify TypeScript library, specifically in versions 0.11.2 through 2.2.3, within the public URL validation logic used to prevent Server-Side Request Forgery (SSRF) attacks. While Fedify blocks common private and local IPv4 ranges, it incorrectly accepts several special-use and reserved ranges as valid public destinations. This flaw can lead to unintended outbound requests to non-public networks, potentially allowing exploitation depending on the deployment environment.
Users should update to Fedify versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, or 2.2.4, which contain the patched validation logic.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 10, 2026CISA-ADP
Assessed Jun 11, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/fedify-dev/fedify/security/advisories/GHSA-xw9q-2mv6-9fr8 | CISA-ADP | AdvisoryBundleExploitRemedyVendor |
| https://github.com/fedify-dev/fedify/security/advisories/GHSA-xw9q-2mv6-9fr8 | [email protected] | AdvisoryBundleExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1286 | Improper Validation of Syntactic Correctness of Input | [email protected] |
| CWE-1389 | Incorrect Parsing of Numbers with Different Radices | [email protected] |
| CWE-918 | Server-Side Request Forgery (SSRF) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Fedify | >= 0.11.2, <= 2.2.3 (semver) |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 21, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 11, 2026 | CVE Modified | CISA-ADP |
| Jun 10, 2026 | New CVE Received | [email protected] |