{"id":"CVE-2026-24048","aliases":["GHSA-q2x5-4xjx-c6p9"],"url":"https://o3.security/vulnerability/CVE-2026-24048","summary":"Backstage has a Possible SSRF when reading from allowed URL's in `backend.reading.allow`","details":"Backstage is an open framework for building developer portals, and @backstage/backend-defaults provides the default implementations and setup for a standard Backstage backend app. Prior to versions 0.12.2, 0.13.2, 0.14.1, and 0.15.0, the `FetchUrlReader` component, used by the catalog and other plugins to fetch content from URLs, followed HTTP redirects automatically. This allowed an attacker who controls a host listed in `backend.reading.allow` to redirect requests to internal or sensitive URLs that are not on the allowlist, bypassing the URL allowlist security control. This is a Server-Side Request Forgery (SSRF) vulnerability that could allow access to internal resources, but it does not allow attackers to include additional request headers. This vulnerability is fixed in `@backstage/backend-defaults` version 0.12.2, 0.13.2, 0.14.1, and 0.15.0. Users should upgrade to this version or later. Some workarounds are available. Restrict `backend.reading.allow` to only trusted hosts that you control and that do not issue redirects, ensure allowed hosts do not have open redirect vulnerabilities, and/or use network-level controls to block access from Backstage to sensitive internal endpoints.","published":"2026-01-21T22:51:44.015Z","modified":"2026-07-15T01:48:53.324769968Z","cvss":{"score":3.5,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@backstage/backend-defaults","fixedVersion":"0.12.2"},{"ecosystem":"npm","name":"@backstage/backend-defaults","fixedVersion":"0.13.2"},{"ecosystem":"npm","name":"@backstage/backend-defaults","fixedVersion":"0.14.1"}],"fix":{"url":"https://github.com/backstage/backstage/commit/27f9061d24affd1b9212fe0abd476bfc3fbaedcb","label":"backstage/backstage@27f9061"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/24xxx/CVE-2026-24048.json"},{"type":"ADVISORY","url":"https://github.com/backstage/backstage/security/advisories/GHSA-q2x5-4xjx-c6p9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-24048"},{"type":"FIX","url":"https://github.com/backstage/backstage/commit/27f9061d24affd1b9212fe0abd476bfc3fbaedcb"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:48:53.324769968Z"}}