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8.8
HIGH CVSS 3.1
CVE-2026-12856
Vscode-java: vscode: command injection vulnerability in the javadoc hover provider of the vscode-java extension
Overview
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.

Details
INFO

Published Date :

June 29, 2026, 2:16 p.m.

Last Modified :

July 15, 2026, 2:18 a.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Impact
Affected Products

The following products are affected by CVE-2026-12856 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Redhat openshift_dev_spaces
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1 HIGH MITRE-CVE
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Solution
Update the vscode-java extension to a version that properly sanitizes JavaDoc hover content.
  • Update the vscode-java extension immediately.
  • Avoid opening untrusted Java files in VS Code.
  • Review VS Code security settings for extensions.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-12856.

URL Resource
https://access.redhat.com/errata/RHSA-2026:36820
https://access.redhat.com/security/cve/CVE-2026-12856 Mitigation Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Issue Tracking Vendor Advisory
https://github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6qrw-3crv Broken Link
https://access.redhat.com/errata/RHSA-2026:36820
https://access.redhat.com/security/cve/CVE-2026-12856 Mitigation Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Issue Tracking Vendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-12856 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-12856 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-12856 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-12856 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jul. 15, 2026

    Action Type Old Value New Value
    Changed Affected [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3.29::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces 3.29', 'defaultStatus': 'affected'}] [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3.29::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces 3.29', 'versions': [{'status': 'unaffected', 'version': '1782989367', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'devspaces/pluginregistry-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}]
  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jul. 09, 2026

    Action Type Old Value New Value
    Added Reference https://access.redhat.com/errata/RHSA-2026:36820
    Changed Affected [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces', 'defaultStatus': 'affected'}] [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3.29::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces 3.29', 'defaultStatus': 'affected'}]
  • CVE Modified by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added Reference https://access.redhat.com/errata/RHSA-2026:36820
    Changed Affected [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces', 'packageName': 'devspaces/pluginregistry-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}] [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3.29::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces 3.29', 'versions': [{'status': 'unaffected', 'version': '1782989367', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'devspaces/pluginregistry-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}]
  • Initial Analysis by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:redhat:openshift_dev_spaces:-:*:*:*:*:*:*:*
    Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-12856 Types: Mitigation, Vendor Advisory
    Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Types: Issue Tracking, Vendor Advisory
    Added Reference Type Red Hat, Inc.: https://github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6qrw-3crv Types: Broken Link
    Added Reference Type redhat-SADP: https://access.redhat.com/security/cve/CVE-2026-12856 Types: Mitigation, Vendor Advisory
    Added Reference Type redhat-SADP: https://bugzilla.redhat.com/show_bug.cgi?id=2491278 Types: Issue Tracking, Vendor Advisory
    Added Reference Type redhat-SADP: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json Types: Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 30, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-12856', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-29T14:49:26.177865Z'} {'id': 'CVE-2026-12856', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-29T00:00:00+00:00'}
  • CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Jun. 30, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces', 'defaultStatus': 'affected'}]
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
    Added CWE CWE-88
    Added Reference https://access.redhat.com/security/cve/CVE-2026-12856
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2491278
    Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12856.json
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 29, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-12856', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-29T14:49:26.177865Z'}
  • New CVE Received by [email protected]

    Jun. 29, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:/a:redhat:openshift_devspaces:3'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces', 'packageName': 'devspaces/pluginregistry-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}]
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
    Added CWE CWE-88
    Added Reference https://access.redhat.com/security/cve/CVE-2026-12856
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2491278
    Added Reference https://github.com/redhat-developer/vscode-java/security/advisories/GHSA-7qv8-6qrw-3crv
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 8.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact