CVE-2026-106455 Backstage: Improper validation of MkDocs plugin configuration in TechDocs
An authenticated attacker can exploit improper validation in Backstage TechDocs to perform Server-Side Request Forgery and read data from internal network locations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-106455?
CVE-2026-106455 is a high-severity server-side request forgery vulnerability in Linuxfoundation Backstage, published on 6 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Backstage is an open framework for building developer portals. From 0.11.12 until 1.14.7 and 1.15.5, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs plugin configuration in techdocs. An authenticated attacker with control over a TechDocs source repository could cause a documentation build to retrieve and publish data from network locations reachable by the build environment. Exposure depends on deployment topology, build mode, and target endpoint protections. Modern cloud metadata services that require tokens or special headers are not directly accessible through the affected behavior. This issue is fixed in @backstage/plugin-techdocs-node versions 1.14.7 and 1.15.5.
Weakness: CWE-918
Which versions are affected by CVE-2026-106455?
4 open source packages ship an affected version, including @backstage/plugin-techdocs-node. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
@backstage/plugin-techdocs-node npm | From 0.11.12 | 1.14.7 |
@backstage/plugin-techdocs-node npm | From 0.11.12 | 1.14.7 |
@backstage/plugin-techdocs-node npm | From 1.15.0 | 1.15.5 |
@backstage/plugin-techdocs-node npm | From 1.15.0 | 1.15.5 |
Products include Linuxfoundation Backstage, Linuxfoundation Backstage Plugin-Techdocs-Node.
How do I fix CVE-2026-106455?
Upgrade @backstage/plugin-techdocs-node to a fixed version for your release line: 1.14.7 or 1.15.5.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-106455 being exploited?
There is no known exploitation of CVE-2026-106455 in the wild and no public exploit code.
Other vulnerabilities in Linuxfoundation Backstage
- CVE-2026-106501 Backstage: Sensitive information exposure in Scaffolder
- CVE-2026-106558 Backstage: Improper validation of TechDocs MkDocs configuration
- CVE-2026-88064 Backstage: Improper input validation in TechDocs MkDocs configuration
- CVE-2026-106459 Backstage: Improper input validation in Sentry scaffolder actions
- CVE-2026-106486 Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Sources
Also known as GHSA-q38j-6vcm-2f5m.