{"cve":"CVE-2026-115923","nvd":{"published":"2026-10-26T18:17:40.360","modified":"2026-10-26T18:39:42.503","status":"Awaiting Analysis","description":"Backstage is an open framework for building developer portals. Prior to 3.9.2 and from 4.0.0 until 4.0.2, DefaultCatalogRulesEnforcer in @backstage/plugin-catalog-backend compares the raw location.target URL against catalog.rules, while URL readers canonicalize the same URL before fetching it. An authenticated user with catalog.location.create permission can use percent-encoded path segments to make an untrusted URL match a trusted location pattern even though the canonical URL resolves outside that scope. This admits entity content from an untrusted source as trusted, while further downstream consequences depend on deployment configuration. This issue is fixed in versions 3.9.2 and 4.0.2.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-22"],"references":["https://github.com/backstage/backstage/commit/3214dc8f15d4a08a2fd07a72a8fe4d00aeac0db4","https://github.com/backstage/backstage/commit/737ff1c719dbd5a97f375b7f1db6d61416618419","https://github.com/backstage/backstage/releases/tag/v1.54.10","https://github.com/backstage/backstage/releases/tag/v1.56.1","https://github.com/backstage/backstage/security/advisories/GHSA-w658-mh9p-ww8f"],"products":[],"source":"nvd","synced_at":"2026-10-26T18:58:45.632391815+00:00"},"epss":null,"kev":null,"osv":[],"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."]}