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CVE-2026-44903 (GCVE-0-2026-44903)

Vulnerability from cvelistv5 – Published: 2026-05-26 21:27 – Updated: 2026-05-27 14:20
VLAI
Title
Prometheus: Stored XSS via crafted histogram bucket label values in the heatmap display of the old Prometheus web UI
Summary
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.
Severity
5.1 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-27 14:19 UTC
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version CPE status
prometheus prometheus Affected: >= 2.49.0, < 3.5.3
Affected: >= 3.6.0-rc.0, < 3.11.3
guessed Create a notification for this product.
Show details on NVD website
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                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
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}



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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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