GHSA-jqhp-238x-qhgf BIT-dotnet-2026-62886 BIT-dotnet-sdk-2026-62886 CVE-2026-62886
Microsoft Security Advisory CVE-2026-62886 – .NET Elevation of Privilege Vulnerability
- Severity
- 7.8 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.47%
- Chance of exploitation in the next 30 days. Higher than 40.42% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Fix
- Available
- 3 packages have a fixed version
Description
Executive summary
Microsoft is releasing this security advisory to provide information about a vulnerability in Windows Presentation Foundation. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
An integer overflow or wraparound in .NET allows an unauthorized attacker to elevate privileges locally.
Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/430
CVSS Details
- Version: 3.1
- Severity: High
- Score: 7.8
- Vector:
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness: CWE-190: Integer Overflow or Wraparound; 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 10"></a>.NET 10
| Package name | Affected version | Patched version |
|---|---|---|
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.10 | 10.0.11 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.10 | 10.0.11 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.10 | 10.0.11 |
<a name=".NET 9"></a>.NET 9
| Package name | Affected version | Patched version |
|---|---|---|
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.18 | 9.0.19 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.18 | 9.0.19 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.18 | 9.0.19 |
<a name=".NET 8"></a>.NET 8
| Package name | Affected version | Patched version |
|---|---|---|
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.29 | 8.0.30 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.29 | 8.0.30 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.29 | 8.0.30 |
Advisory FAQ
<a name="how-affected"></a>How do I know if I am affected?
If using a package listed in affected packages, an application is exposed to the vulnerability.
<a name="how-fix"></a>How do I fix the issue?
- To fix the issue please install the latest version of .NET. If users have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt them to update Visual Studio, which will also update their .NET SDKs.
- If a user's application references the vulnerable package, update the package reference to the patched version. Users can list the versions they have installed by running the
dotnet --infocommand.
Once users have installed the updated runtime or SDK, they should restart their apps for the update to take effect.
Additionally, if they've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.
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. Further information can be found in the MSRC Report an Issue FAQ.
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
Acknowledgements
zpbrent; kai63001; 41ae55e9310ff27fa6f26af4727e5590; Ky0toFu
Revisions
V1.0 (08/11/2026): Advisory published.
Affected versions
NuGet
| Package | Vulnerable | Fixed in |
|---|---|---|
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 10.0.0, < 10.0.11 |
10.0.11 |
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 9.0.0, < 9.0.19 |
9.0.19 |
| Microsoft.WindowsDesktop.App.Runtime.win-arm64 | >= 8.0.0, < 8.0.30 |
8.0.30 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 10.0.0, < 10.0.11 |
10.0.11 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 9.0.0, < 9.0.19 |
9.0.19 |
| Microsoft.WindowsDesktop.App.Runtime.win-x64 | >= 8.0.0, < 8.0.30 |
8.0.30 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 10.0.0, < 10.0.11 |
10.0.11 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 9.0.0, < 9.0.19 |
9.0.19 |
| Microsoft.WindowsDesktop.App.Runtime.win-x86 | >= 8.0.0, < 8.0.30 |
8.0.30 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
Microsoft.WindowsDesktop.App.Runtime.win-arm64 NuGet → 10.0.11
- dotnet
dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-arm64 --version 10.0.11
Microsoft.WindowsDesktop.App.Runtime.win-x64 NuGet → 10.0.11
- dotnet
dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x64 --version 10.0.11
Microsoft.WindowsDesktop.App.Runtime.win-x86 NuGet → 10.0.11
- dotnet
dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x86 --version 10.0.11
Severity breakdown
CVSS 3.1 7.8
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-122: Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
How to prevent it
- Pre-design: Use a language or compiler that performs automatic bounds checking.
- Architecture and Design: Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Operation, Build and Compilation: Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
- Operation, Build and Compilation: Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code. Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking. For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].
- Implementation: Implement and perform bounds checking on input.
- Implementation: Do not use dangerous functions such as gets. Look for their safe equivalent, which checks for the boundary.
- Operation: Use OS-level preventative functionality. This is not a complete solution, but it provides some defense in depth.
CWE-190: Integer Overflow or Wraparound
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
How to prevent it
- Requirements: Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
- Requirements: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++). [REF-106]
- Implementation: Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range. Use unsigned integers where possible. This makes it easier to perform validation for integer overflows. When signed integers are required, ensure that the range check includes minimum values as well as maximum values.
- Implementation: Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, "not-a-number" calculations, and how the language handles numbers that are too large or too small for its underlying representation. [REF-7] Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.
- Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Implementation: Examine compiler warnings closely and eliminate problems with potential security implications, such as signed / unsigned mismatch in memory operations, or use of uninitialized variables. Even if the weakness is rarely exploitable, a single failure may lead to the compromise of the entire system.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-g44w-h65v-4cw9 Microsoft Security Advisory CVE-2026-96235 - .NET and Visual Studio Remote Code Execution Vulnerability | High | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
| GHSA-fq6x-pvr9-888r Microsoft Security Advisory CVE-2026-96234 - .NET and Visual Studio Information Disclosure Vulnerability | Medium | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
| GHSA-f8qh-mqg4-9939 Microsoft Security Advisory CVE-2026-96232 - .NET and Visual Studio Information Disclosure Vulnerability | High | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
| GHSA-5qr9-xxm9-6cmq Microsoft Security Advisory CVE-2026-96229 - .NET and Visual Studio Information Disclosure Vulnerability | Medium | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
| GHSA-xq57-crx4-g373 Microsoft Security Advisory CVE-2026-96224 - .NET and Visual Studio Remote Code Execution Vulnerability | High | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
| GHSA-c27m-942f-rcfh Microsoft Security Advisory CVE-2026-87697 - .NET and Visual Studio Remote Code Execution Vulnerability | High | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
| GHSA-f63g-mx39-3r38 Microsoft Security Advisory CVE-2026-85363 - .NET and Visual Studio Remote Code Execution Vulnerability | High | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
| GHSA-4w5f-7jp2-w48g Microsoft Security Advisory CVE-2026-83520 - .NET and Visual Studio Remote Code Execution Vulnerability | High | Also affects Microsoft.WindowsDesktop.App.Runtime.win-arm64 |
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor