CVE-2026-25153
What it is
Backstage is an open framework for building developer portals, and @backstage/plugin-techdocs-node provides common node.js functionalities for TechDocs. In versions of @backstage/plugin-techdocs-node prior to 1.13.11 and 1.14.1, when TechDocs is configured with `runIn: local`, a malicious actor who can submit or modify a repository's `mkdocs.yml` file can execute arbitrary Python code on the TechDocs build server via MkDocs hooks configuration. @backstage/plugin-techdocs-node versions 1.13.11 and 1.14.1 contain a fix. The fix introduces an allowlist of supported MkDocs configuration keys. Unsupported configuration keys (including `hooks`) are now removed from `mkdocs.yml` before running the generator, with a warning logged to indicate which keys were removed. Users of `@techdocs/cli` should also upgrade to the latest version, which includes the fixed `@backstage/plugin-techdocs-node` dependency. Some workarounds are available. Configure TechDocs with `runIn: docker` instead of `runIn: local` to provide container isolation, though it does not fully mitigate the risk. Limit who can modify `mkdocs.yml` files in repositories that TechDocs processes; only allow trusted contributors. Implement PR review requirements for changes to `mkdocs.yml` files to detect malicious `hooks` configurations before they are merged. Use MkDocs < 1.4.0 (e.g., 1.3.1) which does not support hooks. Note: This may limit access to newer MkDocs features. 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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure.
- Exploit odds
- 0.6% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.6% in the next 30 days (EPSS).
- Severity: 7.7 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.6% · EPSS, next 30 days
- Weakness
- CWE-94 · Code injection
- Record status
- Undergoing Analysis
Affected
- Linuxfoundation Backstage < 1.13.11
- Linuxfoundation Backstage < 1.14.1
Attack profile CVSS 3.1 · 7.7
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- Low
- Availability
- Low
Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-25153.md and follow it. Check whether this project is affected by CVE-2026-25153. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
References
- https://github.com/backstage/backstage/security/advisories/GHSA-6jr7-99pf-8vgf
- https://access.redhat.com/errata/RHSA-2026:6174
- https://access.redhat.com/errata/RHSA-2026:6802
- https://access.redhat.com/security/cve/CVE-2026-25153
- https://bugzilla.redhat.com/show_bug.cgi?id=2435576
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25153.json