# Microsoft Visual Studio heap buffer overflow in DiaSymReader

Source: https://junglewise.ai/threats/microsoft-visual-studio-heap-buffer-overflow-in-diasymreader-20fcd9b2  
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

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

Microsoft Visual Studio contains a heap buffer overflow bug in a debugging symbol reader component that could allow an attacker to execute malicious code on a developer's machine over the network. This affects the DiaSymReader.Native library used by Visual Studio for parsing debug information. A successful exploit could give an attacker complete control over the affected system, compromising development environments and potentially sensitive source code or intellectual property.

Technologies: [Microsoft DiaSymReader.Native](https://junglewise.ai/threats/technologies/diasymreader-native), [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 This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** High severity, with a CVSS score of 8.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft DiaSymReader.Native >= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1; Microsoft.DiaSymReader.Native (NuGet) >= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1.

**Is there a fix for This vulnerability?** A patch was published on 2026-09-08: Patch version 18.9.0-beta1.26405.2 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked over the network, in a software library.

**Am I affected?** Check whether you run Microsoft DiaSymReader.Native or Microsoft.DiaSymReader.Native (NuGet) 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.

## Technical details

This is a heap-based buffer overflow vulnerability (CWE-122) in Microsoft's DiaSymReader.Native component, which is responsible for reading debug symbol information in Visual Studio. The vulnerability can be exploited over a network (AV:N) with low attack complexity (AC:L), requiring no special privileges (PR:N) but does require user interaction (UI:R). An attacker can exploit this to achieve arbitrary code execution with high impact on confidentiality, integrity, and availability. The vulnerable version range is Microsoft.DiaSymReader.Native >= 17.10.0-beta1.24272.1 through <= 18.9.0-beta1.26405.1. Microsoft has released a patch in version 18.9.0-beta1.26405.2. Note: This advisory was withdrawn as a duplicate of GHSA-2j8r-3c22-8565.

## Affected products

- Microsoft Microsoft.DiaSymReader.Native >= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1

## Timeline

- 2026-09-08: disclosed
- 2026-09-08: patched: Patch version 18.9.0-beta1.26405.2 released

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69522](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69522)

## Related threats

- [Microsoft Visual Studio heap buffer overflow in DiaSymReader](https://junglewise.ai/threats/microsoft-visual-studio-heap-buffer-overflow-in-diasymreader-b617ae69)
- [Microsoft .NET and Visual Studio heap buffer overflow elevation of privilege](https://junglewise.ai/threats/microsoft-net-and-visual-studio-heap-buffer-overflow-elevation-of-02f3702a)
- [Heap-based buffer overflow in Visual Studio allows an unauthorized attacker to execute code over a network.](https://junglewise.ai/threats/cve-2026-71328-microsoft-diasymreader-native-heap-buffer-overflow)
- [Heap-based buffer overflow in Visual Studio allows an unauthorized attacker to execute code over a network.](https://junglewise.ai/threats/cve-2026-69522-microsoft-diasymreader-native-heap-buffer-overflow-in-pdb)
- [Heap-based buffer overflow in .NET and Visual Studio allows an unauthorized attacker to elevate privileges over a network.](https://junglewise.ai/threats/cve-2026-69439-microsoft-diasymreader-native-heap-overflow-in-pdb-parsing)