CVE-2025-59273
Published: 23 October 2025
Summary
CVE-2025-59273 is a high-severity Improper Access Control (CWE-284) vulnerability in Microsoft Azure Event Grid. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 30.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and AC-6 (Least Privilege).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
AC-3 enforces approved authorizations for access to system resources, directly mitigating improper access control that enables unauthorized privilege elevation.
AC-6 applies least privilege to restrict capabilities, preventing unauthorized attackers from elevating privileges beyond their approved access.
AC-2 manages accounts to ensure only authorized entities have access, reducing risks of improper access controls leading to privilege escalation.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Vulnerability enables unauthorized network-based privilege escalation via improper access control in public-facing Azure service, directly mapping to T1190 (Exploit Public-Facing Application) and T1068 (Exploitation for Privilege Escalation).
NVD Description
Improper access control in Azure Event Grid allows an unauthorized attacker to elevate privileges over a network.
Deeper analysisAI
CVE-2025-59273 is an improper access control vulnerability (CWE-284) in Azure Event Grid. Published on 2025-10-23, it carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L). The flaw stems from inadequate access controls, enabling unauthorized privilege elevation over a network.
An unauthorized attacker with network access can exploit this vulnerability with low complexity, requiring no privileges, user interaction, or special conditions. Exploitation allows the attacker to elevate privileges, leading to low-level impacts on confidentiality, integrity, and availability.
Microsoft's Security Response Center provides mitigation details in its update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59273.
Details
- CWE(s)