November 14, 2026

CVE Watchtower

CVE-2026-118492Eclipse Foundation Eclipse Langium Cross-site Scripting (XSS)

NVD

Vulnerability Summary

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.
Severity Level
LOW(2.0)
Published Date
Nov 9, 2026
Last Modified
Nov 12, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.14%Probability
Root Weakness (CWE)
CWE-79: Cross-site Scripting (XSS) β†—
The software does not neutralize user-controllable input before it is placed in output that is used as a web page.
CVSS v4.0 Base Metrics — Score 2.0 (LOW)
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/AU:N/R:A/V:D
Attack VectorLocal
Attack ComplexityLow
Attack RequirementsPresent
Privileges RequiredNone
User InteractionPassive
Confidentiality (Vulnerable System)None
Integrity (Vulnerable System)None
Availability (Vulnerable System)None
Confidentiality (Subsequent System)Low
Integrity (Subsequent System)Low
Availability (Subsequent System)None

Affected & Patched Versions

Affected Versions
  • Eclipse Foundation Eclipse Langium >= 3.0.0 and <= 4.4.0
Patched Versions
  • Eclipse Foundation Eclipse Langium 4.4.0

What to do

Fix it during your normal patch cycle. No exploitation is confirmed yet.

  1. Check whether you run Eclipse Foundation Eclipse Langium and which version.
  2. Update to a patched version listed above, then confirm the new version.

Timeline

  • Nov 9, 2026Published
  • Nov 12, 2026Record last modified

Score, severity and exploitation changes are tracked from the day Watchtower started logging them.

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External References

Data last checked: Nov 14, 2026 00:39 UTC