CVE-2026-42399 | Uncontrolled Resource Consumption in Kibana Leading to Denial of Service

Uncontrolled Resource Consumption (CWE-400) in Kibana can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated low-privileged user can cause Kibana to consume exponentially increasing amounts of memory by submitting a specially crafted Timelion visualization expression containing deeply chained function calls. The resulting data structure grows without bound, exhausting available memory and causing the Kibana service to crash and become unavailable to all users.

Published: 2026-05-28 Last update: 2026-06-01 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-42399 is rated Low Risk (33.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.30%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42399

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 0.30% +0.26%
2 2026-05-29 0.04%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42399

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-42399

GitHub Security Advisory for CVE-2026-42399

GHSA-hcw2-vpp7-52v9 · Severity: medium — Uncontrolled Resource Consumption (CWE-400) in Kibana can lead to denial of service via Excessive...

Affected software / configurations for CVE-2026-42399

Vendor Product Version Raw CPE
elastic kibana >= 8.0.0, < 8.19.16 cpe:2.3:a:elastic:kibana:*:*:*:*:*:*:*:*
elastic kibana >= 9.0.0, < 9.3.5 cpe:2.3:a:elastic:kibana:*:*:*:*:*:*:*:*

References for CVE-2026-42399

cvelogic Threat Intelligence