CVE-2026-62871
published 2026-08-11CVE-2026-62871: Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.
PriorityP346high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
EPSS
0.40%
33.0th percentile
Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.
Affected
9 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | microsoft_visual_studio_2022_version_17.14 | >= 17.14.0 < 17.14.38 | 17.14.38 |
| microsoft | microsoft_visual_studio_2026_version_18.8 | >= 18.0 < 18.8.3 | 18.8.3 |
| microsoft | net | >= 10.0.0 < 10.0.11 | 10.0.11 |
| microsoft | net | >= 8.0.0 < 8.0.30 | 8.0.30 |
| microsoft | net | >= 9.0.0 < 9.0.19 | 9.0.19 |
| microsoft | net_8.0 | >= 8.0.0 < 8.0.30 | 8.0.30 |
| microsoft | net_9.0 | >= 9.0.0 < 9.0.19 | 9.0.19 |
| microsoft | visual_studio_2022 | >= 17.14.0 < 17.14.38 | 17.14.38 |
| microsoft | visual_studio_2026 | >= 18.8.0 < 18.8.3 | 18.8.3 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
ghsa7.8HIGH
vendor_redhat7.8HIGH
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VulDB
Microsoft .NET/Visual Studio out-of-bounds write (WID-SEC-2026-2761)
vuldb·2026-08-15·CVSS 7.8
CVE-2026-62871 [HIGH] Microsoft .NET/Visual Studio out-of-bounds write (WID-SEC-2026-2761)
A vulnerability identified as problematic has been detected in Microsoft .NET and Visual Studio. This issue affects some unknown processing. This manipulation causes out-of-bounds write.
The identification of this vulnerability is CVE-2026-62871. The attack can only be executed locally. There is no exploit available.
To fix this issue, it is recommended to deploy a patch.
GHSA
Microsoft Security Advisory CVE-2026-62871 – .NET Elevation of Privilege Vulnerability
ghsa·2026-08-11·CVSS 7.8
CVE-2026-62871 [HIGH] CWE-122 Microsoft Security Advisory CVE-2026-62871 – .NET Elevation of Privilege Vulnerability
Microsoft Security Advisory CVE-2026-62871 – .NET Elevation of Privilege Vulnerability
## 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.
Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.
## Announcement
Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/431
## 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-787: Out-of-bounds Write; CWE-122: Heap-based Buffer Overflow
## Affect
Red Hat
dotnet: .NET: Arbitrary Code Execution via Out-of-Bounds Write
vendor_redhat·2026-08-11·CVSS 7.8
CVE-2026-62871 [HIGH] CWE-787 dotnet: .NET: Arbitrary Code Execution via Out-of-Bounds Write
dotnet: .NET: Arbitrary Code Execution via Out-of-Bounds Write
Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.
A flaw was found in .NET. An out-of-bounds write vulnerability allows an unauthorized attacker to execute arbitrary code locally. This could lead to a complete compromise of the affected system.
Statement: Red Hat's .NET packages ship only the cross-platform runtime (Microsoft.NETCore.App.Runtime). CVE-2026-62871 affects exclusively Microsoft.WindowsDesktop.App.Runtime.win-* — the WinForms and WPF GUI subsystem, which is Windows-only and not included in any Red Hat .NET build. No Red Hat product is affected.
Mitigation: No mitigation is required. Red Hat's .NET packages do not ship the Windows Desktop runtime components (Microsoft.WindowsDe
No detection rules found.
No public exploits indexed.
Rapid7
Patch Tuesday - August 2026
blogs_rapid7·2026-08-11·CVSS 7.2
CVE-2026-68821 [HIGH] Patch Tuesday - August 2026
Microsoft is publishing 421 vulnerabilities on August 2026 Patch Tuesday , including 236 vulnerabilities in Windows. This is lower volume than last month’s record-breaking behemoth, but still one of the largest Patch Tuesday totals ever. There is no reason to suppose that Patch Tuesday will ever return to the lower volumes we saw prior to 2026. Microsoft is aware of exploitation in the wild for one of the vulnerabilities published today, as well as public disclosure for two others, although the Notable CVEs section of the Security Update Guide omits one of these. As usual, browser vulns are not included in the Patch Tuesday count above, but unusually, Microsoft does not appear to have published any desktop browser security patches so far this month.
## Summary charts
## Summary tables
#
Sans Isc
Microsoft Patch Tuesday August 2026, (Tue, Aug 11th)
blogs_sans_isc·2026-08-11·CVSS 7.8
CVE-2026-68820 [HIGH] Microsoft Patch Tuesday August 2026, (Tue, Aug 11th)
Microsoft Patch Tuesday August 2026
Published: 2026-08-11. Last Updated: 2026-08-11 17:54:49 UTC
by Renato Marinho (Version: 1)
0 comment(s)
This month we got patches for 418 vulnerabilities. Of these, 62 are critical, 1 is being exploited in the wild, and 2 were publicly disclosed as zero-days. Notable fixes include Windows privilege escalation, container tampering, and critical QUIC and DNS Server remote code execution bugs.
A few vulnerabilities worth mentioning:
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability (CVE-2026-68820)
This Important-severity elevation of privilege vulnerability is listed by Microsoft as exploited in the wild but not publicly disclosed, and it has a CVSS score of 7.0. The flaw is a use-after-free issue in the Windows Ancil
Bugzilla
CVE-2026-62871 dotnet: .NET: Arbitrary Code Execution via Out-of-Bounds Write
bugzilla·2026-08-11·CVSS 7.8
CVE-2026-62871 [HIGH] CVE-2026-62871 dotnet: .NET: Arbitrary Code Execution via Out-of-Bounds Write
CVE-2026-62871 dotnet: .NET: Arbitrary Code Execution via Out-of-Bounds Write
Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.
2026-08-11
Published