CVE-2026-12856

Vscode-java: vscode: command injection vulnerability in the javadoc hover provider of the vscode-java extension

HIGH
8.8
CVSS Score
Published: June 29, 2026 at 12:33 PM UTC
Updated: October 25, 2026 at 09:10 PM UTC
1 product affected across 1 vendorOpenShift Dev Spaces

Using Red Hat OpenShift Dev Spaces by Red Hat?

Get instant alerts when new vulnerabilities affect Red Hat OpenShift Dev Spaces - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH8.8
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions3.29
Vendor states this is fixed in 1782989367 (unaffected)

References (5)

VDB Entryx_refsource_REDHATMitigationVendor Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-12856
Issue Trackingx_refsource_REDHATVendor Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2491278
Vendor Advisory
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:36820

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-88

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card