{"answers":{"affected":"8 open source packages ship an affected version, including @backstage/plugin-scaffolder-backend. It affects 2 products.","exploited":"There is no known exploitation of CVE-2026-106503 in the wild and no public exploit code.","fix":"Upgrade @backstage/plugin-scaffolder-backend to a fixed version for your release line: 3.3.1, 3.4.1, 4.0.3 or 4.1.0.","what":"CVE-2026-106503 is a high-severity authentication bypass vulnerability in Linuxfoundation Backstage, published on 6 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-106503 and fix it if it is affected.\n\nWhat it is: CVE-2026-106503 is a high-severity authentication bypass vulnerability in Linuxfoundation Backstage, published on 6 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-106503 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- @backstage/plugin-scaffolder-backend (npm): affected all versions; fixed in 3.3.1\n- @backstage/plugin-scaffolder-backend (npm): affected all versions; fixed in 3.3.1\n- @backstage/plugin-scaffolder-backend (npm): affected from 3.4.0; fixed in 3.4.1\n- @backstage/plugin-scaffolder-backend (npm): affected from 3.4.0; fixed in 3.4.1\n- @backstage/plugin-scaffolder-backend (npm): affected from 4.0.0; fixed in 4.0.3\n- @backstage/plugin-scaffolder-backend (npm): affected from 4.0.0; fixed in 4.0.3\n- @backstage/plugin-scaffolder-backend (npm): affected from 4.0.4; fixed in 4.1.0\n- @backstage/plugin-scaffolder-backend (npm): affected from 4.0.4; fixed in 4.1.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-106503/ (Markdown: https://insights.sbomify.com/CVE-2026-106503/index.md)","id":"CVE-2026-106503","markdown":"https://insights.sbomify.com/CVE-2026-106503/index.md","name":"CVE-2026-106503","record":{"aliases":["GHSA-hmp2-4m7g-22cv"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["privilege_escalation","data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"Backstage developer portal","requires_auth":"low_privilege","summary":"Authenticated users can bypass Scaffolder action restrictions to gain unauthorized access to repositories and source-control resources.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"backstage","vendor":"linuxfoundation"},{"product":"backstage\\/plugin-scaffolder-backend","vendor":"linuxfoundation"}],"cvss":{"score":8.1,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-284","name":"Improper Access Control"},{"id":"CWE-178","name":"Improper Handling of Case Sensitivity"}],"description":"Backstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1, 4.0.3 and 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by scaffolder action input authorization bypass. An authenticated user with access to affected Scaffolder templates could bypass configured action restrictions. Depending on integration credentials, this could grant unauthorized access to repositories and related source-control resources. This issue is fixed in versions 3.3.1, 3.4.1, 4.0.3 and 4.1.0.","ecosystems":["npm"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Backstage: Scaffolder action input authorization bypass","id":"CVE-2026-106503","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":"linuxfoundation:backstage","products":["linuxfoundation:backstage"],"type":"auth_bypass","year":"2026"},"n_packages":8,"n_references":7,"next":{"headline":"Backstage: Sensitive information exposure in scaffolder task logs","id":"CVE-2026-106504"},"packages":[{"ecosystem":"npm","fixed":["3.3.1"],"introduced":["0"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":null,"source":"GHSA-hmp2-4m7g-22cv"},{"ecosystem":"npm","fixed":["3.3.1"],"introduced":["0"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":"pkg:npm/%40backstage/plugin-scaffolder-backend","source":"GHSA-hmp2-4m7g-22cv"},{"ecosystem":"npm","fixed":["3.4.1"],"introduced":["3.4.0"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":null,"source":"GHSA-hmp2-4m7g-22cv"},{"ecosystem":"npm","fixed":["3.4.1"],"introduced":["3.4.0"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":"pkg:npm/%40backstage/plugin-scaffolder-backend","source":"GHSA-hmp2-4m7g-22cv"},{"ecosystem":"npm","fixed":["4.0.3"],"introduced":["4.0.0"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":null,"source":"GHSA-hmp2-4m7g-22cv"},{"ecosystem":"npm","fixed":["4.0.3"],"introduced":["4.0.0"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":"pkg:npm/%40backstage/plugin-scaffolder-backend","source":"GHSA-hmp2-4m7g-22cv"},{"ecosystem":"npm","fixed":["4.1.0"],"introduced":["4.0.4"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":null,"source":"GHSA-hmp2-4m7g-22cv"},{"ecosystem":"npm","fixed":["4.1.0"],"introduced":["4.0.4"],"last_affected":[],"package":"@backstage/plugin-scaffolder-backend","purl":"pkg:npm/%40backstage/plugin-scaffolder-backend","source":"GHSA-hmp2-4m7g-22cv"}],"prev":{"headline":"Backstage: Sensitive information may be exposed in Scaffolder task failure events","id":"CVE-2026-106502"},"products":["backstage","plugin-scaffolder-backend"],"published":"2026-10-06","related":[{"cvss_score":9.6,"headline":"Backstage: Sensitive information exposure in Scaffolder","id":"CVE-2026-106501","kev_date_added":null,"published":"2026-10-06"},{"cvss_score":8.8,"headline":"Backstage: Improper validation of TechDocs MkDocs configuration","id":"CVE-2026-106558","kev_date_added":null,"published":"2026-10-07"},{"cvss_score":8.8,"headline":"Backstage: Improper input validation in TechDocs MkDocs configuration","id":"CVE-2026-88064","kev_date_added":null,"published":"2026-09-16"},{"cvss_score":8.5,"headline":"Backstage: Improper input validation in Sentry scaffolder actions","id":"CVE-2026-106459","kev_date_added":null,"published":"2026-10-06"},{"cvss_score":8.5,"headline":"Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions","id":"CVE-2026-106486","kev_date_added":null,"published":"2026-10-06"},{"cvss_score":8.5,"headline":"Backstage: Improper task state validation in Scaffolder backend","id":"CVE-2026-106500","kev_date_added":null,"published":"2026-10-06"},{"cvss_score":8.5,"headline":"Path Traversal in @backstage/plugin-scaffolder-backend","id":"CVE-2021-43783","kev_date_added":null,"published":"2021-11-29"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-09","vendors":["@backstage","backstage"]},"summary":"Authenticated users can bypass Scaffolder action restrictions to gain unauthorized access to repositories and source-control resources.","url":"https://insights.sbomify.com/CVE-2026-106503/"}