CVE-2026-40212 OpenStack CVE debrief

Who should care

OpenStack Skyline administrators and users who access the console web interface should assess their exposure to this vulnerability. Additionally, security teams and vulnerability management teams should review the vulnerability and implement necessary mitigations to prevent potential exploits.

Why it matters

Defenders should prioritize verifying exposure in OpenStack Skyline deployments, especially where administrators access the console web interface, and assess potential consequences of XSS attacks.

• Verify exposure in OpenStack Skyline deployments
• Assess administrator access and usage of the console
• Review and update console log viewing practices

Technical summary

The OpenStack Skyline console is vulnerable to DOM-based Cross-Site Scripting (XSS) due to the unsafe use of document.write. This issue can occur when administrators use the console web interface to view instance console logs. The vulnerability can be exploited by injecting malicious scripts into the console logs, potentially leading to unauthorized actions or data breaches. Defenders should prioritize verifying exposure in OpenStack Skyline deployments, especially where administrators access the console web interface.

Defensive priority

Defenders should prioritize verifying exposure in OpenStack Skyline deployments, especially where administrators access the console web interface.

Recommended defensive actions

• Verify OpenStack Skyline version and exposure to the console web interface
• Assess administrator access and usage of the console
• Review and update console log viewing practices to minimize risk
• Implement compensating controls for exposed systems while remediation is scheduled and verified
• Monitor relevant logs for exposed assets that need extra review
• Track exceptions and retest remediated assets
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. However, additional information on affected versions and remediation is limited. Further verification is needed to determine the full scope of affected systems and to implement effective mitigations. The OpenStack security advisory and related source references should be consulted for additional guidance.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.