CVE-2023-35926
criticalpriority · track · 41EPSS 0.019 · 79 %ileEUUSEPSS · scored 2026-10-27
Backstage is an open platform for building developer portals. The Backstage scaffolder-backend plugin uses a templating library that requires sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities that may not have a fix, the plugin has switched to using a different sandbox library. A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8–9.9
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-wg6p-jmpc-xjmrBackstage Scaffolder plugin has insecure sandbox2023-06-21ghsa · osvUS
The Backstage scaffolder-backend plugin uses a templating library that requires a sandbox, as it by design allows for code injection. The library used for this sandbox so far has been `vm2`, but in light of several past vulnerabilities and existing vulnerabilities that may not have a fix, the plugin has switched to using a different sandbox library. ### Impact A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template YAML definition itself and not by user input data. ### Patches This is vulnerability is fixed in version 1.15.0 of `@backstage/plugin-scaffolder-backend`. ### Workarounds Note that the [Backstage Threat Model](https://backstage.io/docs/overview/threat-model) states that scaffolder templates are considered to be a sensitive area that with the recommendation that you control access and perform manual reviews of changes to the scaffolder templates. The exploit is of a nature where it is easily discoverable in manual review.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2023-35926/cnnvd
- https://github.com/backstage/backstage/commit/fb7375507d56faedcb7bb3665480070593c8949acnnvd
- https://github.com/backstage/backstage/releases/tag/v1.15.0cnnvd
- https://github.com/backstage/backstage/security/advisories/GHSA-wg6p-jmpc-xjmrcnnvd
- https://github.com/backstage/backstage/commit/fb7375507d56faedcb7bb3665480070593c8949aenisa_euvd
- https://github.com/backstage/backstage/releases/tag/v1.15.0enisa_euvd
- https://github.com/backstage/backstage/security/advisories/GHSA-wg6p-jmpc-xjmrenisa_euvd
- https://github.com/backstage/backstage/commit/fb7375507d56faedcb7bb3665480070593c8949aPatchnvd
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