CliInvoke: Improper Neutralization of Argument Delimiters in a Command
CVE-2026-100369 is a high-severity improper neutralization of argument delimiters in a command vulnerability in CliInvoke from Alastairlundy, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. Affected CliInvoke versions: >= 2.0.0, <= 2.8.4; >= 2.9.0, <= 2.9.3; >= 2.10.0, <= 2.10.4, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.36% 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
- Check which version of CliInvoke you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Alastairlundy | CliInvoke | >= 2.0.0, <= 2.8.4; >= 2.9.0, <= 2.9.3; >= 2.10.0, <= 2.10.4; >= 3.0.0-alpha.1, <= 3.0.0-beta.1 | Not stated |
| Alastairlundy | AlastairLundy.CliInvoke | >= 2.0.0-alpha.1, <= 2.0.0 | Not stated |
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
- NoneNo account or login is needed.
- 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:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
CliInvoke and its formerly named `AlastairLundy.CliInvoke` package are .NET libraries for invoking command-line programs and wrapping executable processes. `CliInvoke` versions 2.0.0 through 2.8.4, 2.9.0 through 2.9.3, 2.10.0 through 2.10.4, and 3.0.0-alpha.1 through 3.0.0-beta.1, as well as `AlastairLundy.CliInvoke` versions 2.0.0-alpha.1 through 2.0.0, contain an argument-injection vulnerability in `RunnerProcessFactory` on the 2.x line and `RunnerConfigurationFactory` on the 3.x line. These factories combine runner arguments, a caller-controlled target, and caller-controlled arguments into one `ProcessStartInfo.Arguments` string, allowing a double quote in the target or an argument to terminate an operating-system-level quoted region and inject unintended elements into the runner’s argument vector, potentially resulting in arbitrary command execution when a shell runner is used. The vulnerability is patched in `CliInvoke` versions 2.8.5, 2.9.4, 2.10.5, and 3.0.0-beta.2, and in `AlastairLundy.CliInvoke` version 2.0.2. No complete workaround is available; users unable to upgrade can partially mitigate the issue by removing double quotes from targets and arguments, additionally removing shell metacharacters when using shell runners, or bypassing the vulnerable factory and constructing a `ProcessConfiguration` with an explicit `ArgumentList`.
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
- 9.4 Critical severity
- 9.9 Critical severity
- 7.8 High severity
- 8.8 High severity
- 7.8 High severity
- 8.8 High severity
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