CVE-2026-42399: Uncontrolled Resource Consumption (CWE-400) in Kibana can lead to denial of service via Excessive Allocation (

Routine

MEDIUM 6.5UPGRADE

CVE-2026-42399 is a medium-severity flaw (CVSS 6.5) affecting kibana. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 t

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-400
Published	2026-05-28
Last modified	2026-10-14

Publisher (CNA): Elastic · Vendor: elastic

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-28 21:16 UTCPublished CVE record published
2026-10-14 20:10 UTCUpdated Record last modified

elastic kibana UPGRADE

Affected: >= 8.0.0 and < 8.19.16 · >= 9.0.0 and < 9.3.5

Fixed in: 8.19.16, 9.3.5

Safe to downgrade to: a release before 8.0.0

1. Check installed version

apt-cache policy kibana || rpm -q kibana || kibana --version

2. UPGRADE to 8.19.16 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kibana

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kibana

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 8.0.0 (Debian / Ubuntu)

apt-cache madison kibana sudo apt install kibana=<VERSION_BEFORE_8.0.0> sudo apt-mark hold kibana

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list kibana sudo dnf downgrade kibana-<VERSION_BEFORE_8.0.0> sudo dnf versionlock add kibana

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-42399?

kibana: upgrade to 8.19.16, 9.3.5. Exact commands for each OS are on this page.

Is CVE-2026-42399 being exploited?

CVE-2026-42399 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-42399 affect?

CVE-2026-42399 affects kibana. Severity is medium (CVSS 6.5). 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 submitt

How urgent is CVE-2026-42399?

Priority 29/100. No elevated risk signals yet.

Software pages

Kibana vulnerabilities

Related CVEs

CVE-2026-49091 HIGH 8.0 UPGRADE Improper Output Neutralization for Logs (CWE-117) in Kibana can lead to log injection via Log Injection-Tamper
CVE-2026-49087 MEDIUM 6.5 UPGRADE Allocation of Resources Without Limits or Throttling (CWE-770) in Kibana can lead to a denial of service via E
CVE-2026-56151 MEDIUM 6.5 UPGRADE Improper Input Validation (CWE-20) in Kibana can lead to a denial of service via Input Data Manipulation (CAPE
CVE-2026-49088 MEDIUM 4.4 UPGRADE Insertion of Sensitive Information into Log File (CWE-532) in Kibana can lead to information disclosure
CVE-2026-63139 MEDIUM 6.5 UPGRADE Uncontrolled Resource Consumption (CWE-400) in Kibana can lead to denial of service via Excessive Allocation (

References

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