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.
Fix
Patch, vendor advisory and mitigation references on NVD 5
- https://access.redhat.com/security/cve/CVE-2026-12856 Mitigation, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Issue Tracking, Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-12856 Mitigation, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Issue Tracking, Vendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 8.8 · redhatNVD modified 2026-10-25 21:10
Affected (CPE criteria) 1
cpe:2.3:a:redhat:openshift_dev_spaces:-:*:*:*:*:*:*:*
References 8
- https://access.redhat.com/errata/RHSA-2026:36820
- https://access.redhat.com/security/cve/CVE-2026-12856 Mitigation, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Issue Tracking, Vendor Advisory
- https://github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6qrw-3crv Broken Link
- https://access.redhat.com/errata/RHSA-2026:36820
- https://access.redhat.com/security/cve/CVE-2026-12856 Mitigation, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Issue Tracking, Vendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json Vendor Advisory