CVE-2026-44903

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 v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/prometheus/prometheus/commit/38f23b9075ced1de2b82d2dad8b2bebb1ecd5b7d	Patch
https://github.com/prometheus/prometheus/security/advisories/GHSA-fw8g-cg8f-9j28	Mitigation Patch Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:prometheus:prometheus::::::::
	cpe:2.3:a:prometheus:prometheus::::::::

History

05 Jun 2026, 17:18

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 6.1
First Time		Prometheus Prometheus prometheus
References	~~() https://github.com/prometheus/prometheus/commit/38f23b9075ced1de2b82d2dad8b2bebb1ecd5b7d -~~	() https://github.com/prometheus/prometheus/commit/38f23b9075ced1de2b82d2dad8b2bebb1ecd5b7d - Patch
References	~~() https://github.com/prometheus/prometheus/security/advisories/GHSA-fw8g-cg8f-9j28 -~~	() https://github.com/prometheus/prometheus/security/advisories/GHSA-fw8g-cg8f-9j28 - Mitigation, Patch, Vendor Advisory
CPE		cpe:2.3:a:prometheus:prometheus::::::::

26 May 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-26 22:16

Updated : 2026-06-05 17:18

NVD link : CVE-2026-44903

Mitre link : CVE-2026-44903

CVE.ORG link : CVE-2026-44903

JSON object : View

Products Affected

prometheus

prometheus

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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