# Microsoft Security Advisory CVE-2026-69522 – .NET and Visual Studio Remote Code Execution Vulnerability
## Executive summary
Microsoft is releasing this security advisory to provide information about a vulnerability in Microsoft.DiaSymReader.Native. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
An out of bounds write can occur when processing PDB files.
## Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/439
## CVSS Details
- **Version:** 3.1
- **Severity:** High
- **Score:** 8.8
- **Vector:** `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`
- **Weakness:** CWE-122 (Heap-based Buffer Overflow)
## Affected Platforms
- **Platforms:** Windows
- **Architectures:** All
## <a name="affected-packages"></a>Affected Packages
The vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below
Supported .NET Framework versions listed in the [Microsoft Security Update Guide](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69522) are also affected. Install the September 2026 .NET Framework security update applicable to a project's Windows version.
### <a name=".NET 11 RC1"></a>.NET 11 RC1
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2
### <a name=".NET 10"></a>.NET 10
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.12.0-beta1.24603.5, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2
### <a name=".NET 9"></a>.NET 9
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.12.0-beta1.24603.5, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2
### <a name=".NET 8"></a>.NET 8
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.12.0-beta1.24603.5, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2
## Advisory FAQ
### <a name="how-affected"></a>How do I know if I am affected?
If using a package listed in [affected packages](#affected-packages), a project is exposed to the vulnerability.
### <a name="how-fix"></a>How do I fix the issue?
1. To fix the issue please install the latest version of .NET or Visual Studio. .NET Framework users must install the September 2026 security update applicable to their Windows version.
2. If a developer's application references Microsoft.DiaSymReader.Native, update the package reference to version 18.9.0-beta1.26405.2 or later.
Once users have installed the updated runtime, SDK, Visual Studio, or package, they should restart their apps for the update to take effect.
## Other Information
### Reporting Security Issues
If users have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue).
Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.
### Support
Users can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. Users can ask questions in the linked discussion issue.
### Disclaimer
The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
### External Links
[CVE-2026-69522](https://www.cve.org/CVERecord?id=CVE-2026-69522)
### Acknowledgements
41ae55e9310ff27fa6f26af4727e5590
### Revisions
V1.0 (09/08/2026): Advisory published.
### Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-2j8r-3c22-8565. This link is maintained to preserve external references.
### Original Description
Heap-based buffer overflow in Visual Studio allows an unauthorized attacker to execute code over a network.
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2
Vendor product
Publisher's version information
Shown as published. These rules are not interpreted as NuGet package version ranges.
{
"vendor": "Microsoft",
"product": "Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2",
"platforms": [
"Windows 10 Version 1607 for 32-bit Systems",
"Windows 10 Version 1607 for x64-based Systems",
"Windows Server 2016"
],
"versions": [
{
"version": "3.0.0.0",
"lessThan": "2.0.50727.8984 & 3.0.30729.8980 & 4.7.4145.0",
"versionType": "custom",
"status": "affected"
}
]
}
Microsoft .NET Framework 3.5 AND 4.7.2
Vendor product
Publisher's version information
Shown as published. These rules are not interpreted as NuGet package version ranges.
{
"vendor": "Microsoft",
"product": "Microsoft .NET Framework 3.5 AND 4.7.2",
"platforms": [
"Windows 10 Version 1809 for 32-bit Systems",
"Windows 10 Version 1809 for ARM64-based Systems",
"Windows 10 Version 1809 for x64-based Systems",
"Windows Server 2019"
],
"versions": [
{
"version": "4.7.0",
"lessThan": "2.0.50727.9070 & 3.0.30729.9068 & 4.7.4145.0",
"versionType": "custom",
"status": "affected"
}
]
}
Microsoft .NET Framework 3.5 AND 4.8
Vendor product
Publisher's version information
Shown as published. These rules are not interpreted as NuGet package version ranges.
{
"vendor": "Microsoft",
"product": "Microsoft .NET Framework 3.5 AND 4.8",
"platforms": [
"Windows 10 Version 1809 for 32-bit Systems",
"Windows 10 Version 1809 for ARM64-based Systems",
"Windows 10 Version 1809 for x64-based Systems",
"Windows 10 Version 21H2 for 32-bit Systems",
"Windows 10 Version 21H2 for ARM64-based Systems",
"Windows 10 Version 21H2 for x64-based Systems",
"Windows 10 Version 22H2 for 32-bit Systems",
"Windows 10 Version 22H2 for ARM64-based Systems",
"Windows 10 Version 22H2 for x64-based Systems",
"Windows Server 2019",
"Windows Server 2022"
],
"versions": [
{
"version": "4.8.0",
"lessThan": "2.0.50727.9070 & 3.0.30729.9068 & 4.8.4806.0",
"versionType": "custom",
"status": "affected"
}
]
}
Microsoft .NET Framework 3.5 AND 4.8.1
Vendor product
Publisher's version information
Shown as published. These rules are not interpreted as NuGet package version ranges.
{
"vendor": "Microsoft",
"product": "Microsoft .NET Framework 3.5 AND 4.8.1",
"platforms": [
"Windows 10 Version 21H2 for 32-bit Systems",
"Windows 10 Version 21H2 for ARM64-based Systems",
"Windows 10 Version 21H2 for x64-based Systems",
"Windows 10 Version 22H2 for 32-bit Systems",
"Windows 10 Version 22H2 for ARM64-based Systems",
"Windows 10 Version 22H2 for x64-based Systems",
"Windows 11 Version 23H2 for ARM64-based Systems",
"Windows 11 Version 23H2 for x64-based Systems",
"Windows 11 Version 24H2 for ARM64-based Systems",
"Windows 11 Version 24H2 for x64-based Systems",
"Windows 11 Version 25H2 for ARM64-based Systems",
"Windows 11 Version 25H2 for x64-based Systems",
"Windows Server 2022",
"Windows Server 2025"
],
"versions": [
{
"version": "4.8.1",
"lessThan": "2.0.50727.9183 & 3.0.30729.9169 & 4.8.9347.0",
"versionType": "custom",
"status": "affected"
}
]
}
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2
Vendor product
Publisher's version information
Shown as published. These rules are not interpreted as NuGet package version ranges.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Sep 8, 2026, 5:10:32 PM
dateUpdated: Nov 10, 2026, 9:29:04 PM
1 related source bulletins · separate from aliases
msrc_CVE-2026-69522: .NET and Visual Studio Remote Code Execution Vulnerability
CVE-2026-69522
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Undergoing Analysis
Weakness classifications: CWE-122
Original publisher date fields
published: 2026-09-08T18:19:19.697
lastModified: 2026-10-30T22:17:33.310
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.