CVE-2025-7326: ASP.NET Core Privilege Escalation Flaw

CVE-2025-7326 Overview

CVE-2025-7326 is a weak authentication vulnerability affecting End of Life (EOL) versions of ASP.NET Core. The flaw allows an unauthorized attacker to elevate privileges over a network by exploiting deficient authentication controls in the framework. Microsoft has confirmed there will be no future updates or support provided for the affected components, leaving organizations running EOL ASP.NET Core exposed without an official patch path. The vulnerability is classified under [CWE-1390] (Weak Authentication) and is related to the earlier Microsoft advisory CVE-2025-24070. HeroDevs has published additional details on the issue through its vulnerability directory entry.

Critical Impact

Network-based privilege escalation against EOL ASP.NET Core deployments, with no vendor patch available from Microsoft.

Affected Products

• ASP.NET Core (End of Life versions)
• Web applications built on EOL ASP.NET Core runtimes
• Microsoft .NET hosted services relying on unsupported ASP.NET Core libraries

Discovery Timeline

• 2025-07-08 - CVE-2025-7326 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-7326

Vulnerability Analysis

The vulnerability stems from weak authentication logic inside ASP.NET Core components that have reached End of Life. An unauthorized network attacker can abuse the deficient authentication checks to gain elevated privileges within the application context. The flaw maps to [CWE-1390], which describes authentication mechanisms that rely on insufficiently strong factors or validation routines.

Exploitation requires no prior authentication and no user interaction, but the attack complexity is high, meaning the attacker must satisfy specific runtime conditions to succeed. Successful exploitation can lead to confidentiality and integrity impact on the targeted application and may cause significant availability loss.

Because Microsoft has marked the affected components as out of support, no security update will be issued through the standard Microsoft Security Response Center channel. Organizations still running these components inherit permanent exposure unless they migrate, isolate, or apply a third-party extended support offering such as the HeroDevs Never-Ending Support for .NET.

Root Cause

The root cause is an authentication routine in ASP.NET Core that does not enforce sufficient verification on incoming requests. The weakness allows authentication state or identity claims to be accepted under conditions that should be rejected. Because the affected codebase is EOL, the upstream fix delivered for CVE-2025-24070 was not backported to these versions.

Attack Vector

The attack vector is network-based. A remote attacker sends crafted requests to an ASP.NET Core application running an EOL build. By manipulating authentication-relevant input the attacker bypasses identity validation and acquires privileges associated with another user or role. No verified public exploit code is currently tracked for CVE-2025-7326.

No verified proof-of-concept code is available. Refer to the HeroDevs advisory and the Microsoft update guide for CVE-2025-24070 for the underlying technical context.

Detection Methods for CVE-2025-7326

Indicators of Compromise

• Authentication success events for accounts that did not complete a full credential exchange against the ASP.NET Core application
• Sudden role or claim changes for sessions originating from external networks
• Application logs showing privileged actions executed by accounts without a corresponding sign-in event

Detection Strategies

• Inventory all .NET and ASP.NET Core runtimes in the environment and flag EOL versions for review
• Correlate web server access logs with identity provider logs to surface authentication anomalies
• Hunt for requests that reach privileged endpoints without traversing the expected authentication middleware chain

Monitoring Recommendations

• Forward ASP.NET Core authentication and authorization logs to a centralized analytics platform for retention and correlation
• Alert on privilege escalation patterns such as standard users invoking administrative routes
• Monitor for repeated 401/403 followed by 200 responses against the same endpoint from a single source

How to Mitigate CVE-2025-7326

Immediate Actions Required

• Identify and inventory ASP.NET Core workloads running EOL versions, as no Microsoft patch is forthcoming
• Migrate affected applications to a supported .NET release that includes the fix for the related CVE-2025-24070
• Restrict network exposure of vulnerable endpoints behind authenticated reverse proxies or VPN gateways

Patch Information

Microsoft has confirmed that no official patch will be released because the affected ASP.NET Core components are End of Life. Organizations unable to upgrade should evaluate third-party extended support such as the HeroDevs Never-Ending Support program for .NET, which provides backported security fixes for unsupported runtimes.

Workarounds

• Place vulnerable applications behind a web application firewall configured to enforce strict authentication on privileged routes
• Enforce multi-factor authentication at an upstream identity provider so that application-level weaknesses cannot be solely relied upon for access
• Apply network segmentation to limit which clients can reach the EOL ASP.NET Core endpoints
• Decommission EOL workloads where migration is not feasible