Raw vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-35926 is a high-severity Code Injection (CWE-94) vulnerability in Linuxfoundation Backstage. Its CVSS base score is 8.0 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked in the top 21% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
The vulnerability is a code injection flaw (CWE-94) in the Backstage scaffolder-backend plugin, which previously relied on the vm2 library to sandbox template execution. Affected software is the @backstage/plugin-scaffolder-backend package prior to version 1.15.0; the component allows registered templates to execute code by design, but the sandbox was insufficient to prevent escape.
An attacker with write access to a registered scaffolder template can craft the template YAML definition to achieve remote code execution on the scaffolder-backend instance. Exploitation is limited to the template itself and cannot be triggered through ordinary user-supplied input data; the CVSS 8.0 score reflects the high impact combined with the requirement for high-privilege access and a complex attack path.
Advisories and patches published by the Backstage project state that the issue is resolved in @backstage/plugin-scaffolder-backend 1.15.0 by replacing vm2 with an alternative sandboxing library. The fix is documented in the project’s GitHub security advisory GHSA-wg6p-jmpc-xjmr and the corresponding release notes and commit.
EPSS remains flat at a peak of 0.0915 with no material increase after disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-1899
Vulnerability Data
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…
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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`.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.3.1
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.
Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.
Validates inputs used in dynamic code generation to block injected directives.
Directly prevents execution of attacker-supplied code written into data memory regions.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).
PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.