CVE-2025-36855: microsoft .net 6.0 Buffer Over-read

Vulnerability summary

CVE-2025-36855 is a high (CVSS 8.8) Buffer Over-read vulnerability in microsoft .net 6.0. EPSS estimates a 0.77% chance of exploitation in the next 30 days, higher than 54.9% of scored vulnerabilities.

Timeline

1. 08-09-2025
   PublishedVulnerability first disclosed.
2. 08-09-2025
   Last modifiedVulnerability information updated.

Description

A vulnerability ( CVE-2025-21176 https://www.cve.org/CVERecord ) exists in DiaSymReader.dll due to buffer over-read. Per CWE-126: Buffer Over-read https://cwe.mitre.org/data/definitions/126.html , Buffer Over-read is when a product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. This issue affects EOL ASP.NET 6.0.0 <= 6.0.36 as represented in this CVE, as well as 8.0.0 <= 8.0.11 & <= 9.0.0 as represented in CVE-2025-21176. 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 affects only End Of Life (EOL) software components. The vendor, Microsoft, has indicated there will be no future updates nor support provided upon inquiry.

• CWE-126Buffer Over-readThe product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.