CVE-2026-62897: .NET Framework Remote Code Execution Vulnerability

CVE-2026-62897 is a remote code execution vulnerability in .NET Framework, rated Important by Microsoft, with a CVSS 3.1 base score of 7 (High). An attacker can exploit it by an attacker with local access, without any privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. The EPSS model estimates a 0.37% probability of exploitation activity in the next 30 days, higher than 31% of all scored vulnerabilities. Microsoft released the fix on 11 August 2026 in the August 2026 Patch Tuesday, delivered through 19 security updates (KB5120711, KB5122106, KB5122104, KB5122105 and more). It affects 57 products in 1 product family (Developer Tools).

Key facts

CVE ID: CVE-2026-62897
Severity: High CVSS 7
Microsoft severity: Important
Impact: Remote Code Execution
Exploited in the wild: No
Publicly disclosed: No
Exploitation likelihood: Less Likely
Weakness: CWE-190
EPSS: 0.37% (percentile 31%)
CISA KEV: Not listed
Released: 11 August 2026
Last updated: 13 August 2026
Patch Tuesday: August 2026 Patch Tuesday
Product families: Developer Tools

CVSS score and vector

Microsoft scores CVE-2026-62897 at 7 (temporal 6.1) using CVSS 3.1. Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Metric	Value
Attack vector	Local
Attack complexity	High
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality impact	High
Integrity impact	High
Availability impact	High
Exploit code maturity	Unproven
Remediation level	Official fix
Report confidence	Confirmed

Description

Integer overflow or wraparound in .NET Framework allows an unauthorized attacker to execute code locally.

Frequently asked questions (Microsoft)

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?

A high attack complexity means that successful exploitation is complex and time‑consuming, requiring significant effort and precise conditions for an attacker to reliably exploit the vulnerability.

Affected products (57)

Developer Tools

Product	Security update	Type	Fixed build	Restart
Microsoft .NET Framework 4.8.1 on Windows 11 Version 26H1 for ARM64-based Systems	KB5120711	Security Update	4.8.9344.0	Maybe
Microsoft .NET Framework 4.8.1 on Windows 11 version 26H1 for x64-based Systems	KB5120711	Security Update	4.8.9344.0	Maybe
.NET 10.0 runtime installed on Windows	KB5122106	Security Update	10.0.11	Maybe
.NET 8.0 runtime installed on Windows	KB5122104	Security Update	8.0.30	Maybe
.NET 9.0 runtime installed on Windows	KB5122105	Security Update	9.0.19	Maybe
Microsoft Visual Studio 2026 version 18.8	Security update	Security Update	18.8.3
Microsoft Visual Studio 2022 version 17.14	Security update	Security Update	17.14.38
Microsoft .NET Framework 4.8 on Windows 10 Version 1607 for 32-bit Systems	KB5120702	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 4.8 on Windows 10 Version 1607 for x64-based Systems	KB5120702	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 4.8 on Windows Server 2016	KB5120702	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 4.8 on Windows Server 2016 (Server Core installation)	KB5120702	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012	KB5120704	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012 (Server Core installation)	KB5120704	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012 R2	KB5120706	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012 R2 (Server Core installation)	KB5120706	Security Update	4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for 32-bit Systems	KB5120703	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for x64-based Systems	KB5120703	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for ARM64-based Systems	KB5120703	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019	KB5120703	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019 (Server Core installation)	KB5120703	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022	KB5120705	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022 (Server Core installation)	KB5120705	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for 32-bit Systems	KB5120701	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for ARM64-based Systems	KB5120701	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for x64-based Systems	KB5120701	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for x64-based Systems	KB5120701	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for ARM64-based Systems	KB5120701	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for 32-bit Systems	KB5120701	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0	Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for 32-bit Systems	KB5120698	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for x64-based Systems	KB5120698	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for ARM64-based Systems	KB5120698	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server 2019	KB5120698	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server 2019 (Server Core installation)	KB5120698	Security Update	2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 Version 1607 for 32-bit Systems	KB5120418	Security Update	2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 Version 1607 for x64-based Systems	KB5120418	Security Update	2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016	KB5120418	Security Update	2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016 (Server Core installation)	KB5120418	Security Update	2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0	Maybe
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012	KB5120699	Security Update	4.7.4144.0	Maybe
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 (Server Core installation)	KB5120699	Security Update	4.7.4144.0	Maybe
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2	KB5120700	Security Update	4.7.4144.0	Maybe
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2 (Server Core installation)	KB5120700	Security Update	4.7.4144.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022	KB5120714	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022 (Server Core installation)	KB5120714	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for 32-bit Systems	KB5120709	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for ARM64-based Systems	KB5120709	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for x64-based Systems	KB5120709	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for x64-based Systems	KB5120709	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for ARM64-based Systems	KB5120709	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for 32-bit Systems	KB5120709	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025 (Server Core installation)	KB5120708	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for ARM64-based Systems	KB5120708	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for x64-based Systems	KB5120708	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for ARM64-based Systems	KB5120713	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for x64-based Systems	KB5120713	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for ARM64-based Systems	KB5120710	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for x64-based Systems	KB5120710	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0	Maybe
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025	KB5120708	Security Update	2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0	Maybe

Security updates (19)

KB5120711 (Security Update)
KB5122106 (Security Update)
KB5122104 (Security Update)
KB5122105 (Security Update)
KB5120702 (Security Update)
KB5120704 (Security Update)
KB5120706 (Security Update)
KB5120703 (Security Update)
KB5120705 (Security Update)
KB5120701 (Security Update)
KB5120698 (Security Update)
KB5120418 (Security Update)
KB5120699 (Security Update)
KB5120700 (Security Update)
KB5120714 (Security Update)
KB5120709 (Security Update)
KB5120708 (Security Update)
KB5120713 (Security Update)
KB5120710 (Security Update)

NIST NVD data

NVD status: Analyzed
NVD CVSS: 7 (HIGH)
NVD weakness: CWE-190
Published to NVD: 11 August 2026
NVD last modified: 14 August 2026

Affected configurations (CPE)

Product	Vulnerable versions
.net framework 3.5	all listed versions
.net framework 3.5	all listed versions
.net framework 4.7.2	all listed versions
visual studio 2022	from 17.14.0, before 17.14.38
visual studio 2026	from 18.8.0, before 18.8.3
.net	from 8.0.0, before 8.0.30
.net	from 9.0.0, before 9.0.19
.net	from 10.0.0, before 10.0.11
.net framework 4.8.1	all listed versions
.net framework 3.5	all listed versions
.net framework 4.8	all listed versions

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62897 (Patch, Vendor Advisory)

Acknowledgments

41ae55e9310ff27fa6f26af4727e5590
Ky0toFu

Revision history

Version	Date	Description
1.0	11 August 2026	Information published.
2.0	13 August 2026	Removed Linux and macOS products from the Affected Software table. This is an informational change only.