CVE-2026-33276
Stored XSS in Checkmk 2.5.0 beta enables authenticated users to inject JS in others' searches.
Is CVE-2026-33276 being exploited?
Not confirmed. CVE-2026-33276 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.14% probability of exploitation in the next 30 days.
How severe is CVE-2026-33276?
CVE-2026-33276 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-33276?
Yes. A fix has been recorded for CVE-2026-33276. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-33276 affect?
CVE-2026-33276 affects Checkmk 2.5.0 (beta) before 2.5.0b2. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-33276?
Upgrade to 2.5.0b2 or later; revalidate security post-upgrade.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated user can run arbitrary JavaScript in other users' browsers via Unified Search, risking session theft and UI manipulation.
Patch when possible
- affected>= 2.5.0b1 and < 2.5.0b2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.