High severity · published Jun 29, 2026
CVE-2026-12856
Vscode-java: vscode: command injection vulnerability in the javadoc hover provider of the vscode-java extension
8.8
CVSS
0.5%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat OpenShift Dev Spaces 3.29 · Red Hat
All versions, or not specified · source: vendor, CISA
OD
Openshift Dev Spaces · Redhat
All versions, or not specified · source: NVD
Affected product
RH
Red Hat OpenShift Dev Spaces 3.29
Red Hat
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-12856
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-12856
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:36820
Mitigation
https://access.redhat.com/security/cve/CVE-2026-12856
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2491278
Broken Link
https://github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6qrw-3crv
Vendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json
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