CVE-2026-42401: Improper Neutralization of Input During Web Page Generation (CWE-79) in Kibana can lead to stored HTML injecti

Routine

MEDIUM 4.1UPGRADE

CVE-2026-42401 is a medium-severity flaw (CVSS 4.1) affecting kibana. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper Neutralization of Input During Web Page Generation (CWE-79) in Kibana can lead to stored HTML injection. A user with write access to an Elasticsearch index could persist crafted markup which, when subsequently rendered through an affected Kibana view by another user, was not sufficiently sanitized. Successful exploitation could result in unauthorized UI manipulation and outbound network requests issued from the viewing user's browser ses

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.1% (top 97%)
CISA exploited list	No
Weakness	CWE-79
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 20:16 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-2026-42401?

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

Is CVE-2026-42401 being exploited?

CVE-2026-42401 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-2026-42401 affect?

CVE-2026-42401 affects kibana. Severity is medium (CVSS 4.1). Improper Neutralization of Input During Web Page Generation (CWE-79) in Kibana can lead to stored HTML injection. A user with write access to an Elasticsearch index could persist crafted markup which, when subsequently rendered through an a

How urgent is CVE-2026-42401?

Priority 15/100. No elevated risk signals yet.

Software pages

Elasticsearch vulnerabilities · 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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