Vulnerability Description
A flaw was found in the vscode-java extension, which provides Java language support for Visual Studio Code. The extension incorrectly trusts all Markdown content in JavaDoc hovers, allowing a malicious Java file to include hidden commands. If a user clicks a specially crafted link within a JavaDoc hover popup, an attacker can execute arbitrary VS Code commands, which can lead to full system compromise in trusted workspaces.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Redhat | Openshift Dev Spaces | - |
Related Weaknesses (CWE)
References
- https://access.redhat.com/errata/RHSA-2026:36820
- https://access.redhat.com/security/cve/CVE-2026-12856MitigationVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2491278Issue TrackingVendor Advisory
- https://github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6qBroken Link
- https://access.redhat.com/errata/RHSA-2026:36820
- https://access.redhat.com/security/cve/CVE-2026-12856MitigationVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2491278Issue TrackingVendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.jsonVendor Advisory
FAQ
What is CVE-2026-12856?
CVE-2026-12856 is a vulnerability with a CVSS score of 8.8 (HIGH). A flaw was found in the vscode-java extension, which provides Java language support for Visual Studio Code. The extension incorrectly trusts all Markdown content in JavaDoc hovers, allowing a maliciou...
How severe is CVE-2026-12856?
CVE-2026-12856 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-12856?
Check the references section above for vendor advisories and patch information. Affected products include: Redhat Openshift Dev Spaces.