Vscode-java: vscode: command injection vulnerability in the javadoc hover provider of the vscode-java extension
Summary
| CVE | CVE-2026-12856 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-29 14:16:41 UTC |
| Updated | 2026-07-15 02:18:11 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 8.8 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.002920000 probability, percentile 0.211770000 (date 2026-07-19)
Problem Types: CWE-88 | CWE-88 Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | CVSS | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | [email protected] | Secondary | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Redhat | Openshift Dev Spaces | - | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat OpenShift Dev Spaces 3.29 | unaffected 1782989367 * rpm | Not specified |
| ADP | Red Hat | Red Hat OpenShift Dev Spaces 3.29 | unaffected 1782989367 * rpm | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-12856 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | Mitigation, Vendor Advisory |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | Vendor Advisory |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | Issue Tracking, Vendor Advisory |
| github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6q... | [email protected] | github.com | Broken Link |
| access.redhat.com/errata/RHSA-2026:36820 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank byte256 for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-06-20T17:33:27.000Z | Reported to Red Hat. |
| CNA | 2026-06-29T12:25:07.165Z | Made public. |
| ADP | 2026-06-20T17:33:27.000Z | Reported to Red Hat. |
| ADP | 2026-06-29T12:25:07.165Z | Made public. |
Solutions
ADP: RHSA-2026:36820: Red Hat OpenShift Dev Spaces 3.29
Workarounds
CNA: 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: 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.