Cyber Resilience

CVE-2025-55321

Critical

Published: 09 October 2025

Published
09 October 2025
Modified
23 October 2025
KEV Added
Patch
CVSS Score v3.1 9.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
EPSS Score 0.0007 21.9th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-55321 is a critical-severity Cross-site Scripting (CWE-79) vulnerability in Microsoft Azure Monitor. Its CVSS base score is 9.3 (Critical).

Operationally, ranked at the 21.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Improper neutralization of input during web page generation ('cross-site scripting') in Azure Monitor allows an unauthorized attacker to perform spoofing over a network.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
azure monitor
all versions

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References