CVE-2026-14574
Low
No strong exploitation signal.
CVSS base
6.5
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS — probability of exploitation (30 days)
0.3%
23.3th percentile
CISA KEV
Not listed
Weakness / dates
CWE-1321
Published 2026-08-05 · modified 2026-08-07
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | H | High |
| Availability | N | None |
Timeline
- 2026-08-05 — Published (NVD)
- 2026-08-07 — Last modified (NVD)
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
References
- https://github.com/eclipse-theia/theia/security/advisories/GHSA-f3w9-qfw3-xr32
- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/157
- exploit https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/567
- exploit https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/567