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Fencer Vulns
high 8.8

CVE-2026-12856 json

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

published 2026-06-29 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-40084

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

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.

Patch / fix

  • Red Hat Red Hat OpenShift Dev Spaces 3.29 1782989367

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-12856 updated cvss 8.8

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

  • Red Hat OpenShift Dev Spaces 3.29 devspaces/pluginregistry-rhel9 1782989367
    fixed: vendor fix RHSA-2026:36820
  • Red Hat OpenShift Dev Spaces 3.29 devspaces/udi-rhel9 1782991491, devspaces/code-rhel9 1782498475, devspaces/server-rhel9 1783033397, devspaces/openvsx-rhel9 1783007534, devspaces/traefik-rhel9 1782403274, devspaces/udi-base-rhel9 1782987705, +10 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
4 mo ago

Exploit prediction

0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat OpenShift Dev Spaces 3.29

Classification

Weakness
  • CWE-88 Improper Neutralization of Argument Delimiters in a Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.