What’s Vulnerable › Vulnerabilities

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

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-07 · updated 2026-07-15
• Weakness: CWE-74

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 products

• Linuxfoundation Backstage Plugin-Techdocs-Node: before 1.14.3 — fixed in 1.14.3

How to fix

Upgrade to a fixed version: Linuxfoundation Backstage Plugin-Techdocs-Node 1.14.3. Check the vendor advisory for mitigations.

References

• https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw
• https://access.redhat.com/errata/RHSA-2026:13826
• https://access.redhat.com/errata/RHSA-2026:9742
• https://access.redhat.com/security/cve/CVE-2026-29186
• https://bugzilla.redhat.com/show_bug.cgi?id=2445480
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29186.json

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