Vulnerability Description
In Eclipse Theia versions 0.7.0 and up until including 1.73.1, the `PreferenceUtils.merge` function in `@theia/core` recursively merges preference values without rejecting prototype-related keys (`__proto__`, `constructor`, `prototype`). Because this function is invoked by `PreferenceServiceImpl.doResolve` for every preference resolution across scopes (default, user, workspace, folder), a crafted preference value in a workspace settings file (`.theia/settings.json` or `.vscode/settings.json`) can pollute `Object.prototype` when the user opens the workspace, potentially altering application logic across the Theia process.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Eclipse | Theia | >= 0.7.0, < 1.74.0 |
Related Weaknesses (CWE)
References
- https://github.com/eclipse-theia/theia/security/advisories/GHSA-f3w9-qfw3-xr32Broken Link
- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/157Vendor Advisory
- https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/567ExploitMitigationVendor Advisory
- https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/567ExploitMitigationVendor Advisory
FAQ
What is CVE-2026-14574?
CVE-2026-14574 is a vulnerability with a CVSS score of 6.5 (MEDIUM). In Eclipse Theia versions 0.7.0 and up until including 1.73.1, the `PreferenceUtils.merge` function in `@theia/core` recursively merges preference values without rejecting prototype-related keys (`__p...
How severe is CVE-2026-14574?
CVE-2026-14574 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-14574?
Check the references section above for vendor advisories and patch information. Affected products include: Eclipse Theia.