CVE-2026-12856

Summary

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.

Affected Software

Weaknesses

• CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')

Workarounds

To mitigate this issue, users should avoid opening or interacting with untrusted Java projects or files within Red Hat OpenShift Dev Spaces. Exercise caution and refrain from clicking on unfamiliar links presented in JavaDoc hover popups, particularly when working with code from unverified sources. Disabling the vscode-java extension when not actively engaged in Java development can further reduce exposure, though this will impact Java-related functionality.

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: total

vscode-java: vscode: Command Injection vulnerability in the JavaDoc hover provider of the vscode-java extension

Additional References

• https://access.redhat.com/security/cve/CVE-2026-12856
• https://bugzilla.redhat.com/show_bug.cgi?id=2491278
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json

References

• https://access.redhat.com/security/cve/CVE-2026-12856
• https://bugzilla.redhat.com/show_bug.cgi?id=2491278
• https://github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6qrw-3crv

• ←Previous
• Next→