{"cve":"CVE-2026-50131","nvd":{"published":"2026-06-10T22:17:01.543","modified":"2026-07-21T19:10:00.107","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","score":8.6},"cwes":["CWE-918","CWE-1286","CWE-1389"],"references":["https://github.com/fedify-dev/fedify/security/advisories/GHSA-xw9q-2mv6-9fr8","https://github.com/fedify-dev/fedify/security/advisories/GHSA-xw9q-2mv6-9fr8"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:38:48.522727527+00:00"},"epss":{"cve":"CVE-2026-50131","score":0.00351,"percentile":0.28751,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-xw9q-2mv6-9fr8","url":"https://osv.dev/vulnerability/GHSA-xw9q-2mv6-9fr8","summary":"Fedify has an incomplete SSRF mitigation after GHSA-p9cg-vqcc-grcx: validatePublicUrl allows special-use IPv4 ranges","modified":"2026-07-28T05:30:29.570452989Z","packages":[{"ecosystem":"npm","name":"@fedify/fedify","purl":"pkg:npm/%40fedify/fedify","ranges":[">=0.11.2 <1.9.12"],"fixed":["1.9.12"]},{"ecosystem":"npm","name":"@fedify/fedify","purl":"pkg:npm/%40fedify/fedify","ranges":[">=1.10.0 <1.10.11"],"fixed":["1.10.11"]},{"ecosystem":"npm","name":"@fedify/fedify","purl":"pkg:npm/%40fedify/fedify","ranges":[">=2.0.0 <2.0.19"],"fixed":["2.0.19"]},{"ecosystem":"npm","name":"@fedify/fedify","purl":"pkg:npm/%40fedify/fedify","ranges":[">=2.1.0 <2.1.15"],"fixed":["2.1.15"]},{"ecosystem":"npm","name":"@fedify/fedify","purl":"pkg:npm/%40fedify/fedify","ranges":[">=2.2.0 <2.2.4"],"fixed":["2.2.4"]},{"ecosystem":"npm","name":"@fedify/vocab-runtime","purl":"pkg:npm/%40fedify/vocab-runtime","ranges":["<2.0.19"],"fixed":["2.0.19"]},{"ecosystem":"npm","name":"@fedify/vocab-runtime","purl":"pkg:npm/%40fedify/vocab-runtime","ranges":[">=2.1.0 <2.1.15"],"fixed":["2.1.15"]},{"ecosystem":"npm","name":"@fedify/vocab-runtime","purl":"pkg:npm/%40fedify/vocab-runtime","ranges":[">=2.2.0 <2.2.4"],"fixed":["2.2.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}