CVE-2026-78581: Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana can lead to unauthorized data modificatio

Routine

MEDIUM 4.2UPGRADE

CVE-2026-78581 is a medium-severity flaw (CVSS 4.2) affecting kibana. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana can lead to unauthorized data modification via Accessing Functionality Not Properly Constrained by ACLs (CAPEC-1). Under certain conditions, an authenticated user could reference another user's AI Assistant conversation identifier to access or modify a conversation they do not own. Successful exploitation requires knowledge of a hard-to-guess identifier.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.2 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Weakness	CWE-639
Published	2026-08-25
Last modified	2026-09-02

Publisher (CNA): Elastic · Vendor: elastic

Last updated 2026-09-02 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-25 13:19 UTCPublished CVE record published
2026-09-02 14:10 UTCUpdated Record last modified

elastic kibana UPGRADE

Affected: >= 8.0.0 and < 8.16.3 · >= 8.17.0 and < 8.17.2

Fixed in: 8.16.3, 8.17.2

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 8.16.3 (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-2026-78581?

kibana: upgrade to 8.16.3, 8.17.2. Exact commands for each OS are on this page.

Is CVE-2026-78581 being exploited?

CVE-2026-78581 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-2026-78581 affect?

CVE-2026-78581 affects kibana. Severity is medium (CVSS 4.2). Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana can lead to unauthorized data modification via Accessing Functionality Not Properly Constrained by ACLs (CAPEC-1). Under certain conditions, an authenticated user could re

How urgent is CVE-2026-78581?

Priority 17/100. No elevated risk signals yet.

Software pages

Kibana vulnerabilities

Related CVEs

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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
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References

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