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Vulnerability · Published Mar 7, 2026 · Assigned by GitHub_M

CVE-2026-29186@backstage/plugin-techdocs-node: TechDocs Mkdocs Configuration Key Enables Arbitrary Code Execution

High 7.7

In plain English

A high-severity unrestricted file upload in backstage from backstage. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 59% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.7High
Exploit odds (30 days)0.9%top 41.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npm@backstage/plugin-techdocs-node1.14.3GHSA-928r-fm4v-mvrw

Affected products (as reported)

VendorProductVersions
backstage backstage < 1.14.3

Weakness: CWE-434, CWE-74, CWE-791 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L

References