CVE-2026-62871ImportantRevised 21 Sep
.NET Elevation of Privilege Vulnerability
Assessment
Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.
- Severity
- Important
- CVSS base score
- 7.8CVSS:3.1/
AV:L/ AC:L/ PR:N/ UI:R/ S:U/ C:H/ I:H/ A:H/ E:U/ RL:O/ RC:C - Impact
- Remote Code Execution
- EPSS, next 30 days
- 0.5%Higher than 37.8% of scored CVEs · FIRST model run 26 Sep 2026 · about EPSS
- Exploitability
- Exploitation Less Likely
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- .NET
- Weakness
- CWE-787: Out-of-bounds Write
- Issued by
- Microsoft
- Published
- 11 Aug 2026 · August 2026
- Last revised
- 21 Sep 2026Updated an acknowledgement. This is an informational change only.
Updates that fix it
2 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5122104 | Security Update | — | .NET 8.0 installed on Windows | All CVEs in KB5122104 |
| KB5122105 | Security Update | — | .NET 9.0 installed on Windows | All CVEs in KB5122105 |
Affected products
Developer Tools4 affected products
- .NET 8.0 installed on Windows
- .NET 9.0 installed on Windows
- Microsoft Visual Studio 2022 version 17.14
- Microsoft Visual Studio 2026 version 18.8