CVE-2026-118492

low

Description

In Eclipse Langium versions 3.0.0 and later, the langium-sprotty package does not HTML-escape diagnostic messages before rendering them in the default hover popup provided by `addHoverPopupHandler`. If a Langium grammar allows cross-reference text to contain HTML markup (such as through a STRING terminal), an unresolved cross-reference produces a diagnostic message that includes the literal ref text. When a Sprotty diagram is opened for a malicious source file under these conditions, and a user hovers over the corresponding error marker, attacker-controlled JavaScript can execute in the browser or webview.

References

https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/1018

https://gitlab.eclipse.org/security/cve-assignment/-/work_items/512

https://github.com/eclipse-langium/langium/security/advisories/GHSA-7c4f-7qwx-hmcv

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-120085

Details

Source: Mitre, NVD

Published: 2026-11-09

Updated: 2026-11-12

Risk Information

CVSS v2

Base Score: 5.8

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 6.1

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Severity: Medium

CVSS v4

Base Score: 2

Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Severity: Low

EPSS

EPSS: 0.00139