CVE-2026-63261 Elastic CVE debrief

Who should care

Users of Kibana, especially those with low-privileged authenticated users, should be aware of this vulnerability and take steps to mitigate it. The vulnerability can be exploited by a low-privileged authenticated user, which increases the attack surface. The vulnerability affects Kibana, a popular data visualization and exploration tool. The vulnerability has a CVSS score of 6.5 and a severity of MEDIUM.

Technical summary

CVE-2026-63261 is an Uncontrolled Resource Consumption vulnerability in Kibana, which can lead to denial of service via Excessive Allocation. A low-privileged authenticated user can send a specially crafted request to a Kibana machine learning feature, causing the server to exhaust available memory and become unavailable to all users. The vulnerability has a CVSS score of 6.5 and a severity of MEDIUM. The vulnerability affects Kibana, a popular data visualization and exploration tool. The vulnerability can be exploited by a low-privileged authenticated user, which increases the attack surface.

Defensive priority

Medium priority, as it requires a low-privileged authenticated user to exploit.

Recommended defensive actions

• Inventory and verify Kibana installations
• Restrict access to Kibana machine learning features
• Monitor Kibana server memory usage
• Apply vendor remediation when available
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-21T23:18:02.817Z and has not been modified since then. The NVD entry is currently Awaiting Analysis. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the vendor. The vulnerability affects Kibana, a popular data visualization and exploration tool. The vulnerability has a CVSS score of 6.5 and a severity of MEDIUM. The vulnerability can be exploited by a low-privileged authenticated user, which increases the attack surface. The vulnerability is related to Uncontrolled Resource Consumption, which can lead to denial of service via Excessive Allocation.

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.