CVE-2026-58275 Overview
CVE-2026-58275 is a missing authorization vulnerability in Microsoft Azure DNS. An unauthenticated attacker can elevate privileges across the network without requiring user interaction. The flaw is tracked under CWE-862: Missing Authorization and carries a maximum CVSS 3.1 base score with a scope-changed impact profile affecting integrity and availability.
Critical Impact
An unauthenticated network attacker can bypass authorization controls in Azure DNS to elevate privileges and compromise integrity and availability of resources beyond the vulnerable component's security scope.
Affected Products
- Microsoft Azure DNS (cloud service)
- Refer to the Microsoft Security Update guide for the definitive list of affected components
Discovery Timeline
- 2026-07-24 - CVE-2026-58275 published to the National Vulnerability Database
- 2026-07-25 - Last updated in NVD database
Technical Details for CVE-2026-58275
Vulnerability Analysis
The vulnerability resides in the authorization logic of Azure DNS. The service fails to verify that a requester holds the required permissions before executing a privileged operation. Because Azure DNS is a shared, multi-tenant cloud service reachable over the public network, the missing check exposes management functions to callers who should not have access.
The CVSS vector describes a scope-changed condition. A successful exploit affects resources outside the security authority of the vulnerable component, which is consistent with a tenant-boundary or cross-account authorization gap. Confidentiality is not impacted, but attackers can tamper with DNS records and disrupt name resolution for downstream workloads.
Root Cause
The root cause is classified as CWE-862: Missing Authorization. A code path in Azure DNS accepts a request and performs a sensitive action without evaluating whether the caller is entitled to perform that action against the target resource. Authentication state is not required to trigger the flaw.
Attack Vector
The attack is delivered over the network against Azure DNS endpoints. Attack complexity is low, no privileges are required, and no user interaction is needed. An attacker crafts a request to a vulnerable Azure DNS operation targeting a resource owned by a different principal. The service processes the request as if it were authorized, granting the attacker the ability to modify DNS zones or records they do not own.
No verified public exploit or proof-of-concept has been published. Refer to the Microsoft Security Response Center advisory for authoritative technical details.
Detection Methods for CVE-2026-58275
Indicators of Compromise
- Unexpected create, update, or delete operations on DNS zones and record sets in Azure Activity Log
- DNS record changes attributed to unfamiliar principals, service principals, or IP addresses
- Sudden appearance of new NS, MX, TXT, or CNAME records pointing to attacker-controlled infrastructure
- Resolution anomalies where internal hostnames resolve to unexpected external endpoints
Detection Strategies
- Ingest Azure Activity Log and Azure DNS diagnostic logs into a centralized SIEM and alert on DNS resource modifications outside change-management windows
- Baseline the set of identities authorized to modify each DNS zone and alert on deviations
- Correlate DNS record changes with subsequent traffic redirection or certificate issuance events
Monitoring Recommendations
- Enable resource-level diagnostic settings on all Azure DNS zones and forward logs to an immutable store
- Monitor for zone transfers, bulk record modifications, and delegation changes on production domains
- Review Microsoft Defender for Cloud alerts related to DNS and identity anomalies
How to Mitigate CVE-2026-58275
Immediate Actions Required
- Review the Microsoft Security Update guide entry to confirm remediation status for your tenant
- Audit recent modifications to Azure DNS zones and records for the 30 days preceding the disclosure date
- Rotate any secrets or certificates whose validation depended on DNS records that could have been tampered with
- Verify role assignments on DNS Zone Contributor and Owner roles, removing stale or over-privileged principals
Patch Information
Azure DNS is a Microsoft-operated cloud service. Remediation is applied by Microsoft on the service side and does not require customer-installed patches. Confirm the fix status and any required tenant actions in the Microsoft Security Response Center advisory.
Workarounds
- Apply least-privilege role assignments on DNS zones using Azure RBAC and remove broad subscription-level DNS write permissions
- Enable Azure Resource Manager resource locks on critical DNS zones to require an explicit unlock before modification
- Deploy Azure Policy rules that deny or audit DNS record changes outside approved automation pipelines
- Enforce Conditional Access and Privileged Identity Management for principals with DNS write permissions
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
