CVE-2026-29186
@backstage/plugin-techdocs-node: TechDocs Mkdocs Configuration Key Enables Arbitrary Code Execution
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.7 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L |
| redhat-SADPADP (enrichment) | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.87% · top 41% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.7.
Weakness
- CWE-434: Unrestricted Upload of File with Dangerous Type (opens in a new tab)All about CWE-434 and its CVEs
- CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') (opens in a new tab)All about CWE-74 and its CVEs
- CWE-791: Incomplete Filtering of Special Elements (opens in a new tab)All about CWE-791 and its CVEs
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npm@backstage/plugin-techdocs-nodeGHSA-928r-fm4v-mvrw (opens in a new tab)
References (6)
- https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw (opens in a new tab)x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2026-29186 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2445480 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29186.json (opens in a new tab)x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:9742 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:13826 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-928r-fm4v-mvrw (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-29186)Record last updated .