CVE-2026-14574

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 v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/eclipse-theia/theia/security/advisories/GHSA-f3w9-qfw3-xr32	Broken Link
https://gitlab.eclipse.org/security/cve-assignment/-/work_items/157	Vendor Advisory
https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/567	Exploit Mitigation Vendor Advisory Issue Tracking
https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/567	Exploit Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:eclipse:theia:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-08-05 11:16

Updated : 2026-08-07 16:02

NVD link : CVE-2026-14574

Mitre link : CVE-2026-14574

CVE.ORG link : CVE-2026-14574

JSON object : View

Products Affected

eclipse

theia

CWE

CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

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