.NET and Visual Studio Elevation of Privilege Vulnerability

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

Heap-based buffer overflow in .NET and Visual Studio allows an unauthorized attacker to elevate privileges over a network.

Source published

8 Sep 2026 17:17:35 UTC

Source modified

10 Nov 2026 21:36:38 UTC

Observed here

10 Nov 2026 23:21:22 UTC

Source terms

CVE Program Terms of Use

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Heap-based buffer overflow in .NET and Visual Studio allows an unauthorized attacker to elevate privileges over a network.

Source published

Sep 8, 2026, 5:17:35 PM (timezone not stated)

Source modified

Oct 31, 2026, 4:16:12 PM (timezone not stated)

Observed here

9 Nov 2026 15:05:34 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Heap-based buffer overflow in .NET and Visual Studio allows an unauthorized attacker to elevate privileges over a network.

Source published

8 Sep 2026 18:19:07 UTC

Source modified

30 Oct 2026 22:17:25 UTC

Observed here

31 Oct 2026 18:05:11 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

# Microsoft Security Advisory CVE-2026-69439 – .NET and Visual Studio Elevation of Privilege 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 parsing a Portable PDB file. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/438 ## 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 ### <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. 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 developers have installed the updated runtime, SDK, Visual Studio, or package, they should restart their apps in order 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-2026-69439](https://www.cve.org/CVERecord?id=CVE-2026-69439) ### Acknowledgements 41ae55e9310ff27fa6f26af4727e5590 ### Revisions V1.0 (09/08/2026): Advisory published.

Source published

9 Sep 2026 16:03:46 UTC

Source modified

1 Oct 2026 10:10:51 UTC

Observed here

23 Oct 2026 16:01:25 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Publisher rating · HIGH

### Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-527h-q9f6-p7qx. This link is maintained to preserve external references. ### Original Description Heap-based buffer overflow in .NET and Visual Studio allows an unauthorized attacker to elevate privileges over a network.

Source published

8 Sep 2026 18:32:35 UTC

Source modified

9 Sep 2026 16:15:05 UTC

Observed here

23 Oct 2026 16:01:25 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Publisher rating · HIGH