What’s Vulnerable › Vulnerabilities

CVE-2026-14574

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-08-05 · updated 2026-10-23
• Weakness: CWE-1321

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.

Affected products

• Eclipse Foundation Eclipse Theia: from 0.7.0 before 1.74.0 — fixed in 1.74.0

How to fix

Upgrade to a fixed version: Eclipse Foundation Eclipse Theia 1.74.0. Check the vendor advisory for mitigations.

References

• https://github.com/eclipse-theia/theia/security/advisories/GHSA-f3w9-qfw3-xr32
• https://gitlab.eclipse.org/security/cve-assignment/-/work_items/157
• https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/567
• https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/567

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