CVE-2023-35926

criticalpriority · track · 41EPSS 0.019 · 79 %ileEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
1.89% (79th) EPSS
CVSS 9.9 · critical
Is it mine?
3 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · nvd · osv

EPSS · 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`.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.9
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8–9.9

v3.19.9criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.1 · impact 6
v3.18.1highCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:Hsecondary · ENISA EU
v3.18highCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:Hsecondary · security-advisories@github.comexploitability 1.3 · impact 6
v3.18highCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:Hsecondary · OSV
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (3)

Products and version ranges known to be affected.

05

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.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

published 2023-06-22modified 2026-06-17
09

references (10)

External citations — patches, advisories, analysis.

scry

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