CVE-2026-12856Network attack vector

Code execution via trusted JavaDoc command links

Published Jun 29, 2026 · Updated Jun 29, 2026

Command injection in Red Hat OpenShift Dev Spaces allows remote attackers to execute VS Code commands through a crafted JavaDoc hover link. The JavaDoc hover provider marks all rendered Markdown as trusted, so command-scheme links embedded in source comments remain executable instead of being rejected. Exploitation requires a user to open the malicious Java file in a trusted workspace and click the crafted hover link, after which attacker-chosen VS Code commands can compromise the workspace.

CVSS severity8.8
High
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Red Hat OpenShift Dev Spaces allows remote attackers to execute VS Code commands through a crafted JavaDoc hover link. The JavaDoc hover provider marks all rendered Markdown as trusted, so command-scheme links embedded in source comments remain executable instead of being rejected. Exploitation requires a user to open the malicious Java file in a trusted workspace and click the crafted hover link, after which attacker-chosen VS Code commands can compromise the workspace.

The record

CVE
CVE-2026-12856
Published
Jun 29, 2026
Updated
Jun 29, 2026
Vendor
389 Directory Server
Product
Red Hat OpenShift Dev Spaces
Classifications
CWE-88, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

389 Directory Server · Red Hat OpenShift Dev SpacesAffected versions are unavailable in this record.

Published CVSS scores

8.8Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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