XSS in Grafana Oss

CVE-2026-17033

An authenticated attacker with Editor access or alert.instances.external:write can submit an external Alertmanager alert containing a controlled generatorURL. The attacker is authorized to create the alert, but not to execute script in another user's Grafana session. Grafana renders alert.generatorURL directly as the Alert Details See source LinkButton href without URL-scheme sanitization or a safe-protocol allowlist. The click interceptor's :// heuristic can be bypassed by placing :// inside a JavaScript comment. When a user with read access clicks See source, the browser executes attacker-controlled JavaScript in the Grafana origin with the clicking user's permissions.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (11.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 11.2% 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-2026-17033: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-17033?
CVE-2026-17033 is a medium-severity vulnerability in Grafana Oss, classified under Cross-site Scripting. CVSS score: 6.8/10. Published 2026-08-24.
How severe is CVE-2026-17033?
Medium severity. CVSS v3 base score is 6.8 out of 10.