CVE-2025-55321: Azure Monitor Log Analytics Spoofing Vulnerability

Overview

Severity
Critical (CVSS 9.3)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C
Category
Spoofing
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2025-Oct
Released
2025-10-09
EPSS Score
0.06% (percentile: 17.7%)

Description

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

FAQ

Why are there no links to an update or instructions with steps that must be taken to protect from this vulnerability? This vulnerability has already been fully mitigated by Microsoft. There is no action for users of this service to take. The purpose of this CVE is to provide further transparency. Please see Toward greater transparency: Unveiling Cloud Service CVEs for more information.

Affected Products (1)

Azure

  • Azure Monitor

Acknowledgments

<a href="https://arnaud.sh/">Arnaud PASCAL</a> with <a href="https://vaadata.com/">VAADATA</a>, <a href="https://github.com/voljeans">Thomas DELFINO</a> with <a href="https://vaadata.com/">VAADATA</a>

Revision History

  • 2025-10-09: Information published.