CVE-2026-106459 Backstage: Improper input validation in Sentry scaffolder actions
An authenticated user can trigger Server-Side Request Forgery in Backstage Sentry actions, potentially disclosing integration credentials.
- 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-2026-106459?
CVE-2026-106459 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 0.3.0 until 0.3.8, the @backstage/plugin-scaffolder-backend-module-sentry package is affected by improper input validation in sentry scaffolder actions. An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token. This issue is fixed in version 0.3.8.
Which versions are affected by CVE-2026-106459?
2 open source packages ship an affected version, including @backstage/plugin-scaffolder-backend-module-sentry. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
@backstage/plugin-scaffolder-backend-module-sentry npm | From 0.3.0 | 0.3.8 |
@backstage/plugin-scaffolder-backend-module-sentry npm | From 0.3.0 | 0.3.8 |
Products include Linuxfoundation Backstage, Linuxfoundation Backstage\/Plugin-Scaffolder-Backend-Module-Sentry.
How do I fix CVE-2026-106459?
Upgrade @backstage/plugin-scaffolder-backend-module-sentry to 0.3.8 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-106459 being exploited?
There is no known exploitation of CVE-2026-106459 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-2026-106486 Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
- CVE-2026-106500 Backstage: Improper task state validation in Scaffolder backend
Sources
Also known as GHSA-g734-fhp4-7mfp.