{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-29186", "tracking": { "current_release_date": "2026-03-24T10:34:56.304737Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-29186", "initial_release_date": "2026-03-05T00:39:58.476941Z", "revision_history": [ { "date": "2026-03-05T00:39:58.476941Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (5).| CWES updated (1)." }, { "date": "2026-03-05T00:40:05.910452Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-05T06:20:56.526459Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (4).| CWES updated (1)." }, { "date": "2026-03-05T06:21:04.779711Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-03-07T15:24:46.342594Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)." }, { "date": "2026-03-07T15:24:49.385545Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-03-07T15:38:46.592729Z", "number": "7", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (1).| CWES updated (1)." }, { "date": "2026-03-07T15:38:53.489618Z", "number": "8", "summary": "NCSC Score updated." }, { "date": "2026-03-08T14:49:31.202216Z", "number": "9", "summary": "Source created.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-08T14:49:38.990968Z", "number": "10", "summary": "NCSC Score updated." }, { "date": "2026-03-09T17:02:47.056300Z", "number": "11", "summary": "References created (1)." }, { "date": "2026-03-09T17:02:49.216734Z", "number": "12", "summary": "NCSC Score updated." }, { "date": "2026-03-09T18:21:08.309599Z", "number": "13", "summary": "References created (1)." }, { "date": "2026-03-09T20:38:50.119406Z", "number": "14", "summary": "Unknown change." }, { "date": "2026-03-10T00:28:03.077245Z", "number": "15", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (4).| Product Identifiers created (2).| Product Remediations created (4).| References created (3).| CWES updated (1).| Vendor_assessment created." }, { "date": "2026-03-10T00:28:10.523501Z", "number": "16", "summary": "NCSC Score updated." }, { "date": "2026-03-11T18:25:01.652817Z", "number": "17", "summary": "Products created (1).| Product Identifiers created (1)." }, { "date": "2026-03-11T18:25:05.396194Z", "number": "18", "summary": "NCSC Score updated." }, { "date": "2026-03-20T09:35:25.726533Z", "number": "19", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-20T09:35:28.283090Z", "number": "20", "summary": "NCSC Score updated." }, { "date": "2026-03-24T10:34:55.547265Z", "number": "21", "summary": "NCSC Score updated." } ], "status": "interim", "version": "21" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/>=0|<1.14.3", "product": { "name": "vers:unknown/>=0|<1.14.3", "product_id": "CSAFPID-5760887" } } ], "category": "product_name", "name": "@backstage/plugin-techdocs-node" } ], "category": "vendor", "name": "backstage" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<1.14.3", "product": { "name": "vers:unknown/<1.14.3", "product_id": "CSAFPID-5769859" } } ], "category": "product_name", "name": "Backstage" } ], "category": "vendor", "name": "Backstage" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/1", "product": { "name": "vers:rpm/1", "product_id": "CSAFPID-1508265", "product_identification_helper": { "cpe": "cpe:/a:redhat:rhdh:1" } } } ], "category": "product_name", "name": "Red Hat Developer Hub" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/2", "product": { "name": "vers:rpm/2", "product_id": "CSAFPID-5486263", "product_identification_helper": { "cpe": "cpe:/a:redhat:ansible_portal:2" } } } ], "category": "product_name", "name": "Self-service automation portal 2" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-5486265" } } ], "category": "product_name", "name": "automation-portal" } ], "category": "product_family", "name": "Self-service automation portal 2" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1508266" } } ], "category": "product_name", "name": "rhdh-hub-rhel9" } ], "category": "product_family", "name": "Red Hat Developer Hub" } ], "category": "vendor", "name": "Red Hat" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<1.14.3", "product": { "name": "vers:unknown/<1.14.3", "product_id": "CSAFPID-5797560", "product_identification_helper": { "cpe": "cpe:2.3:a:linuxfoundation:backstage_plugin-techdocs-node:*:*:*:*:*:*:*:*" } } } ], "category": "product_name", "name": "backstage_plugin-techdocs-node" } ], "category": "vendor", "name": "linuxfoundation" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-29186", "cwe": { "id": "CWE-434", "name": "Unrestricted Upload of File with Dangerous Type" }, "notes": [ { "category": "description", "text": "### Impact\nThis is a configuration bypass vulnerability that enables arbitrary code execution. The `@backstage/plugin-techdocs-node` package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. \n\nA gap in this allowlist allows attackers to craft an `mkdocs.yml` that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. \n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-node` version 1.14.3\n\n### Workarounds\nIf users cannot upgrade immediately:\n\n1. Use Docker mode with restricted access: Configure TechDocs with `runIn: docker` instead of `runIn: local`. This provides container isolation, though it does not fully mitigate the risk.\n2. Restrict repository access: Limit who can modify `mkdocs.yml` files in repositories that TechDocs processes. Only allow trusted contributors.\n3. Manual review: Implement PR review requirements for changes to `mkdocs.yml` files to detect malicious hooks configurations before they are merged.\n4. Downgrade MkDocs: Use MkDocs < 1.4.0 (e.g., 1.3.1) which does not support hooks. Note: This may limit access to newer MkDocs features.\n\nNote: Building documentation in CI/CD pipelines using `@techdocs/cli` does not mitigate this vulnerability, as the CLI uses the same vulnerable `@backstage/plugin-techdocs-node` package.\n\n### Resources\n[MkDocs Hooks Documentation](https://www.mkdocs.org/user-guide/configuration/#hooks)\n[MkDocs 1.4 Release Notes](https://www.mkdocs.org/about/release-notes/#version-14-2022-09-27)\n[TechDocs Architecture](https://backstage.io/docs/features/techdocs/architecture)", "title": "github - https://github.com/advisories/GHSA-928r-fm4v-mvrw" }, { "category": "description", "text": "### Impact\nThis is a configuration bypass vulnerability that enables arbitrary code execution. The `@backstage/plugin-techdocs-node` package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. \n\nA gap in this allowlist allows attackers to craft an `mkdocs.yml` that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. \n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-node` version 1.14.3\n\n### Workarounds\nIf users cannot upgrade immediately:\n\n1. Use Docker mode with restricted access: Configure TechDocs with `runIn: docker` instead of `runIn: local`. This provides container isolation, though it does not fully mitigate the risk.\n2. Restrict repository access: Limit who can modify `mkdocs.yml` files in repositories that TechDocs processes. Only allow trusted contributors.\n3. Manual review: Implement PR review requirements for changes to `mkdocs.yml` files to detect malicious hooks configurations before they are merged.\n4. Downgrade MkDocs: Use MkDocs < 1.4.0 (e.g., 1.3.1) which does not support hooks. Note: This may limit access to newer MkDocs features.\n\nNote: Building documentation in CI/CD pipelines using `@techdocs/cli` does not mitigate this vulnerability, as the CLI uses the same vulnerable `@backstage/plugin-techdocs-node` package.\n\n### Resources\n[MkDocs Hooks Documentation](https://www.mkdocs.org/user-guide/configuration/#hooks)\n[MkDocs 1.4 Release Notes](https://www.mkdocs.org/about/release-notes/#version-14-2022-09-27)\n[TechDocs Architecture](https://backstage.io/docs/features/techdocs/architecture)", "title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/npm%2FGHSA-928r-fm4v-mvrw.json?alt=media" }, { "category": "description", "text": "Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. This issue has been patched in version 1.14.3.", "title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-29186" }, { "category": "description", "text": "Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. This issue has been patched in version 1.14.3.", "title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-29186" }, { "category": "description", "text": "Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. This issue has been patched in version 1.14.3.\nA flaw was found in Backstage. The backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml file that causes arbitrary Python code execution.\nTo exploit this issue, an attacker needs commit access to a repository that Backstage is configured to track and build in order to introduce a malicious mkdocs.yml file into the TechDocs build pipeline. Additionally, an attacker can execute arbitrary Python code but the payload is confined by the permissions granted to the TechDocs build process which is typically a restricted service account, limiting the impact of this vulnerability. Due to these reasons, this vulnerability has been rated with an important severity.", "title": "redhat - https://access.redhat.com/security/cve/CVE-2026-29186" }, { "category": "other", "text": "0.0006", "title": "EPSS" }, { "category": "other", "text": "4.1", "title": "NCSC Score" }, { "category": "other", "text": "Is related to (a version of) an uncommon product, Is related to CWE-434 (Unrestricted Upload of File with Dangerous Type), Is related to an uncommon product vendor, There is product_remediation data available from source Redhat", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 3\n", "title": "Vendor assessment" } ], "product_status": { "known_affected": [ "CSAFPID-5760887", "CSAFPID-5769859", "CSAFPID-1508265", "CSAFPID-1508266", "CSAFPID-5486263", "CSAFPID-5486265", "CSAFPID-5797560" ] }, "references": [ { "category": "external", "summary": "Source - github", "url": "https://github.com/advisories/GHSA-928r-fm4v-mvrw" }, { "category": "external", "summary": "Source raw - github", "url": "https://api.github.com/advisories/GHSA-928r-fm4v-mvrw" }, { "category": "external", "summary": "Source - osv", "url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/npm%2FGHSA-928r-fm4v-mvrw.json?alt=media" }, { "category": "external", "summary": "Source - nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-29186" }, { "category": "external", "summary": "Source raw - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-29186" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://www.cve.org/CVERecord?id=CVE-2026-29186" }, { "category": "external", "summary": "Source raw - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/29xxx/CVE-2026-29186.json" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-29186" }, { "category": "external", "summary": "Source raw - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/security/cve/CVE-2026-29186" }, { "category": "external", "summary": "Source raw - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-29186.json" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd; osv; redhat", "url": "https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw" }, { "category": "external", "summary": "Reference - github; osv", "url": "https://backstage.io/docs/features/techdocs/architecture" }, { "category": "external", "summary": "Reference - github; osv", "url": "https://www.mkdocs.org/about/release-notes/#version-14-2022-09-27" }, { "category": "external", "summary": "Reference - github; osv", "url": "https://www.mkdocs.org/user-guide/configuration/#hooks" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/advisories/GHSA-928r-fm4v-mvrw" }, { "category": "external", "summary": "Reference - github; osv; redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-29186" }, { "category": "external", "summary": "Reference - redhat", "url": "https://www.cve.org/CVERecord?id=CVE-2026-29186" } ], "remediations": [ { "category": "mitigation", "details": "To mitigate this issue, enable docker isolation by updating the Backstage configuration to use 'runIn: docker' instead of 'runIn: local', confining the arbitrary Python code execution to a containerized environment. Additionally, limit commit access to repositories tracked by Backstage to trusted contributors only, and enforce mandatory pull request (PR) reviews for any modifications made to the mkdocs.yml file.", "product_ids": [ "CSAFPID-1508265", "CSAFPID-1508266", "CSAFPID-5486263", "CSAFPID-5486265" ] } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L", "baseScore": 9.1, "baseSeverity": "CRITICAL" }, "products": [ "CSAFPID-1508265", "CSAFPID-1508266", "CSAFPID-5486263", "CSAFPID-5486265", "CSAFPID-5760887", "CSAFPID-5769859", "CSAFPID-5797560" ] } ], "title": "CVE-2026-29186" } ] }