Vulnerability Description
Prometheus is an open-source monitoring system and time series database. From 2.49.0 to before 3.5.3 and 3.11.3, in the Prometheus server's legacy web UI (enabled via the command-line flag --enable-feature=old-ui), the histogram heatmap chart view does not escape le label values when inserting them into the HTML for use as axis tick mark labels. An attacker who can inject crafted metrics can execute JavaScript in the browser of any Prometheus user who views the metric in the heatmap chart UI. This vulnerability is fixed in 3.5.3 and 3.11.3.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Prometheus | Prometheus | >= 2.49.0, < 3.5.3 |
Related Weaknesses (CWE)
References
- https://github.com/prometheus/prometheus/commit/38f23b9075ced1de2b82d2dad8b2bebbPatch
- https://github.com/prometheus/prometheus/security/advisories/GHSA-fw8g-cg8f-9j28MitigationPatchVendor Advisory
FAQ
What is CVE-2026-44903?
CVE-2026-44903 is a vulnerability with a CVSS score of 6.1 (MEDIUM). Prometheus is an open-source monitoring system and time series database. From 2.49.0 to before 3.5.3 and 3.11.3, in the Prometheus server's legacy web UI (enabled via the command-line flag --enable-fe...
How severe is CVE-2026-44903?
CVE-2026-44903 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-44903?
Check the references section above for vendor advisories and patch information. Affected products include: Prometheus Prometheus.