Windows 10 Version 21H2: Improper Neutralization of Argument Delimiters in a Command
CVE-2026-97798 is a high-severity improper neutralization of argument delimiters in a command vulnerability in Windows 10 Version 21H2 from Microsoft, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 10.0.19044.7807 as the first without the flaw, so updating Windows 10 Version 21H2 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.47% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Windows 10 Version 21H2 to 10.0.19044.7807 or a later version.
- Update Windows 10 Version 22H2 to 10.0.19045.7807 or a later version.
- Update Windows 11 version 23H2 to 10.0.22631.7652 or a later version.
- Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Windows 10 Version 21H2 | 10.0.19044.0 up to, but not including, 10.0.19044.7807 | 10.0.19044.7807 |
| Microsoft | Windows 10 Version 22H2 | 10.0.19045.0 up to, but not including, 10.0.19045.7807 | 10.0.19045.7807 |
| Microsoft | Windows 11 version 23H2 | 10.0.22631.0 up to, but not including, 10.0.22631.7652 | 10.0.22631.7652 |
| Microsoft | Windows 11 Version 24H2 | 10.0.26100.0 up to, but not including, 10.0.26100.9711 | 10.0.26100.9711 |
| Microsoft | Windows 11 Version 25H2 | 10.0.26200.0 up to, but not including, 10.0.26200.9711 | 10.0.26200.9711 |
| Microsoft | Windows 11 version 26H1 | 10.0.28000.0 up to, but not including, 10.0.28000.3231 | 10.0.28000.3231 |
| Microsoft | Windows 11 Version 26H2 | 10.0.26300.0 up to, but not including, 10.0.26300.9711 | 10.0.26300.9711 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 up to, but not including, 10.0.20348.5761 | 10.0.20348.5761 |
| Microsoft | Windows Server 2025 | 10.0.26100.0 up to, but not including, 10.0.26100.33650 | 10.0.26100.33650 |
| Microsoft | Windows Server 2025 (Server Core installation) | 10.0.26100.0 up to, but not including, 10.0.26100.33650 | 10.0.26100.33650 |
| Microsoft | Windows 10 21h2 | before 10.0.19044.7807 | 10.0.19044.7807 |
| Microsoft | Windows 10 22h2 | before 10.0.19045.7807 | 10.0.19045.7807 |
| Microsoft | Windows 11 23h2 | before 10.0.22631.7652 | 10.0.22631.7652 |
| Microsoft | Windows 11 24h2 | before 10.0.26100.9711 | 10.0.26100.9711 |
| Microsoft | Windows 11 25h2 | before 10.0.26200.9711 | 10.0.26200.9711 |
| Microsoft | Windows 11 26h1 | before 10.0.28000.3231 | 10.0.28000.3231 |
| Microsoft | Windows 11 26h2 | before 10.0.26300.9711 | 10.0.26300.9711 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (microsoft.com).
Official description
Improper neutralization of argument delimiters in a command ('argument injection') in Windows Error Reporting allows an authorized attacker to elevate privileges locally.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Argument Delimiters in a Command
The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
How developers prevent this class of flaw
- Understand all the potential areas where untrusted inputs can enter your product: parameters or arguments, cookies, anything read from the network, environment variables, request headers as well as content, URL components, e-mail, files, databases, and any external systems that provide data to the application. Perform input validation at well-defined interfaces.
- Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
- When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.
More Improper Neutralization of Argument Delimiters in a Command vulnerabilities (CWE-88)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Recent Improper Neutralization of Argument Delimiters in a Command vulnerabilities
- 9.0 Critical severity
- 8.8 High severity
- 7.1 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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