# CVE-2026-71328: Heap-based buffer overflow in Visual Studio allows an unauthorized attacker to execute code over a network.

Source: https://junglewise.ai/threats/cve-2026-71328-microsoft-diasymreader-native-heap-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-71328 · Severity: high · CVSS 8.8 · Published 2026-09-08

Microsoft DiaSymReader.Native is a library used by .NET and Visual Studio to read debugging symbol information from PDB files. A heap buffer overflow vulnerability allows an attacker to craft a malicious PDB file that, when processed by the library, overwrites memory and executes arbitrary code. This affects developers and CI/CD pipelines that process untrusted or compromised symbol files, potentially leading to code injection and system compromise.

Technologies: [Microsoft Visual Studio](https://junglewise.ai/threats/technologies/visual-studio), [Microsoft Visual Studio 2022](https://junglewise.ai/threats/technologies/visual-studio-2022), [Microsoft Windows](https://junglewise.ai/threats/technologies/windows), [Microsoft.DiaSymReader.Native (NuGet)](https://junglewise.ai/threats/technologies/microsoft-diasymreader-native). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft), [NuGet](https://junglewise.ai/threats/vendors/nuget).

## Quick answers

**Is CVE-2026-71328 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-71328 being exploited in the wild.

**How severe is CVE-2026-71328?** High severity, with a CVSS score of 8.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Visual Studio versions using affected Microsoft.DiaSymReader.Native; Microsoft.DiaSymReader.Native (NuGet) >= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1, ECOSYSTEM:introduced=17.10.0-beta1.24272.1,fixed=18.9.0-beta1.26405.2.

**Is there a fix for CVE-2026-71328?** Yes. Microsoft.DiaSymReader.Native (NuGet): upgrade to 18.9.0-beta1.26405.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-71328 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-71328?** Check whether you run Microsoft Visual Studio, Microsoft Visual Studio 2022, Microsoft Visual Studio 2026 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Microsoft.DiaSymReader.Native (NuGet): upgrade to 18.9.0-beta1.26405.2 or later

  ```sh
  dotnet add package Microsoft.DiaSymReader.Native --version 18.9.0-beta1.26405.2
  ```


## Technical details

This vulnerability is a heap-based buffer overflow (CWE-122) triggered during MSFZ PDB file processing in Microsoft.DiaSymReader.Native. The root cause is insufficient bounds checking when writing to heap-allocated buffers. Attack vector is network-based (AV:N) with low complexity (AC:L), requiring only user interaction (UI:R) such as opening a project with a malicious PDB file or fetching symbols from an untrusted source. No privileges are required. A successful exploit enables arbitrary code execution in the context of the affected application or development environment. The vulnerability impacts .NET 8, 9, 10, and 11 RC1. Patches are available: update Microsoft.DiaSymReader.Native to version 18.9.0-beta1.26405.2 or later, or upgrade to the latest .NET SDK/Visual Studio.

## Affected products

- Microsoft Microsoft.DiaSymReader.Native >= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1
- Microsoft .NET 11 RC1 uses affected Microsoft.DiaSymReader.Native
- Microsoft .NET 10 uses affected Microsoft.DiaSymReader.Native
- Microsoft .NET 9 uses affected Microsoft.DiaSymReader.Native
- Microsoft .NET 8 uses affected Microsoft.DiaSymReader.Native
- Microsoft Visual Studio versions using affected Microsoft.DiaSymReader.Native

## Identifiers

- CVE-2026-71328
- GHSA-63gh-g2x5-x69v

## Timeline

- 2026-09-08: disclosed: Microsoft security advisory published
- 2026-09-08: patched: Patch released: Microsoft.DiaSymReader.Native version 18.9.0-beta1.26405.2

## References

- [https://github.com/dotnet/runtime/security/advisories/GHSA-63gh-g2x5-x69v](https://github.com/dotnet/runtime/security/advisories/GHSA-63gh-g2x5-x69v)
- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-71328](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-71328)
- [https://api.github.com/repos/dotnet/runtime/security-advisories/GHSA-63gh-g2x5-x69v](https://api.github.com/repos/dotnet/runtime/security-advisories/GHSA-63gh-g2x5-x69v)

## Related threats

- [Microsoft Visual Studio heap buffer overflow RCE](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-224be73b)
- [Microsoft Visual Studio heap-based buffer overflow](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-6a4b9d28)
- [Microsoft Visual Studio deserialization remote code execution](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-1eb2f932)
- [Microsoft Visual Studio stack-based buffer overflow](https://junglewise.ai/threats/duplicate-advisory-microsoft-security-advisory-visual-studio-remote-d956164d)
- [Windows BitLocker heap buffer overflow with physical attack](https://junglewise.ai/threats/cve-2026-97015-heap-based-buffer-overflow-in-windows-bitlocker-allows-an)