CVE-2025-36854

CVSS 8.1 High
  • CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
  • Published: 2025-09-08T14:15:34.380

A vulnerability ( CVE-2024-38229 https://www.cve.org/CVERecord ) exists in EOL ASP.NET when closing an HTTP/3 stream while application code is writing to the response body, a race condition may lead to use-after-free, resulting in Remote Code Execution.

Per CWE-416: Use After Free https://cwe.mitre.org/data/definitions/416.html , Use After Free is when a product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

This issue affects EOL ASP.NET 6.0.0 <= 6.0.36 as represented in this CVE, as well as 8.0.0 <= 8.0.8, 9.0.0-preview.1.24081.5 <= 9.0.0.RC.1 as represented in  CVE-2024-38229 https://www.cve.org/CVERecord .

Additionally, if you've deployed self-contained applications https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd  targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

NOTE: This CVE only represents End Of Life (EOL) software components. The vendor, Microsoft, has indicated there will be no future updates nor support provided upon inquiry.

Related CVE by CWE

No related CWE found.

Top CVE for Vendor

No vendor taxonomy on this entry.

Recently Exploited Similar Vulnerabilities

No recent KEV-listed items for this vendor/product.

How to fix CVE-2025-36854

CVE-2025-36854 is a high severity vulnerability affecting the affected product.

Description: A vulnerability ( CVE-2024-38229 https://www.cve.org/CVERecord ) exists in EOL ASP.NET when closing an HTTP/3 stream while application code is writing to the response body, a race condition may lead to use-after-free, resulting in Remote Code Execution. Per CWE-416: Use After Free https://cwe.mitre.org/data/definitions/416.html , Use After Free is when a product reuses or references memory after […]

Exploit Difficulty: MEDIUM
⏱️ Time to exploit: 1-4 hours
🛠️ Required skills: Intermediate security knowledge
💰 Public exploits: May be available

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Vendor Advisory: https://www.cve.org/CVERecord

Exploit Difficulty Assessment

MEDIUM
⏱️ Time to Exploit: 1-4 hours
🛠️ Skills Required: Intermediate security knowledge
💰 Public Exploits: May be available

Vulnerability Timeline

Sep 08, 2025
Vulnerability Published

CVE details first published to NVD database

Nov 12, 2025
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.