Auth bypass in Checkmk

CVE-2026-7765

Incorrect authorization in the User Messages dashboard widget in Checkmk <2.5.0p5 causes the message-fetching endpoints to return the dashboard creator's messages rather than the viewer's, allowing an attacker who knows a valid public dashboard share token to read the issuer's personal messages by sending requests to the underlying endpoint, even without a User Messages widget present.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (23.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-7765: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-7765?
CVE-2026-7765 is a medium-severity vulnerability in Checkmk, classified under Incorrect Authorization. CVSS score: 5.3/10. Published 2026-06-08.
How severe is CVE-2026-7765?
Medium severity. CVSS v3 base score is 5.3 out of 10.