CVE-2026-118492
In Eclipse Langium versions 3.0.0 and later, the langium-sprotty package does not HTML-escape...
CVE-2026-118492 is a low vulnerability (CVSS 2.0) in Eclipse Foundation Langium, published November 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.14%, the 3rd percentile. No source names a fixed version.
- Severity
- 2.0 LowCVSS 4.0, CVE List
- Exploit chance
- 0.14%EPSS, 3rd percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
Affected products
What each source reports
CVE List Score used
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.
- Record
CVE-2026-118492- CVSS 4.0
- 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 - Weakness
- CWE-79
- Updated
- 2026-11-12
EUVDEUVD-2026-120085
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.
- Record
EUVD-2026-120085- CVSS 4.0
- 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 - Updated
- 2026-11-09
GitHub AdvisoriesGHSA-cw7r-mhgg-m7v3
In Eclipse Langium versions 3.0.0 and later, the langium-sprotty package does not HTML-escape...
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.
- Record
GHSA-cw7r-mhgg-m7v3- CVSS 4.0
- 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:A/V:D/RE:X/U:X - Weakness
- CWE-79
- Updated
- 2026-11-09
NVD
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.
- Record
CVE-2026-118492- CVSS 4.0
- 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:A/V:D/RE:X/U:X - Weakness
- CWE-79
- Updated
- 2026-11-12
OSV
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.
- Record
CVE-2026-118492- CVSS 4.0
- 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 - Weakness
- CWE-79
- Updated
- 2026-11-11
History
| Recorded | Changed | Sources |
|---|---|---|
| references | CVE List, OSV | |
| aliases, references | OSV | |
| published | EUVD | |
| published | EUVD | |
| aliases, references, title | GitHub Advisories, NVD | |
| aliases, published | EUVD | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
gitlab.eclipse.org/security/vulnerability-reports/-/work_items/1018
github.com/eclipse-langium/langium/security/advisories/GHSA-7c4f-7qwx-hmcv
nvd.nist.gov/vuln/detail/CVE-2026-118492