CliInvoke is a .NET library for invoking command-line programs, and its `CliInvoke.Specializations` packages provide specialized wrappers for shells such as PowerShell and Windows Command Prompt. `CliInvoke.Specializations` versions 2.2.0 through 2.8.4, 2.9.0 through 2.9.3, 2.10.0 through 2.10.4, 3.0.0-alpha.1 through 3.0.0-alpha.4, and 3.0.0-alpha.8 through 3.0.0-alpha.10, as well as `AlastairLundy.CliInvoke.Specializations` versions 1.0.0-rc.1 through 1.6.1.1, contain an OS command injection vulnerability in their PowerShell and Cmd wrappers. The wrappers pass a caller-controlled target and arguments to `pwsh -Command` or `cmd /c` using a single `ProcessStartInfo.Arguments` string, allowing a double quote in untrusted input to break operating-system-level quoting and cause the shell to execute an additional command with the host process's privileges. The vulnerability is patched in `CliInvoke.Specializations` versions 2.8.5, 2.9.4, 2.10.5, and 3.0.0-beta.1, and in `AlastairLundy.CliInvoke.Specializations` version 2.0.2. No complete workaround is available; users unable to upgrade should reject or remove double quotes from target paths and arguments, additionally reject shell metacharacters in versions 2.2.0 through 2.9.2 and 3.0.0-alpha.1 through 3.0.0-alpha.4, or bypass the PowerShell and Cmd wrappers and invoke target processes directly when handling untrusted input.
CliInvoke is a .NET library for invoking command-line programs, and its `CliInvoke.Specializations` packages provide specialized wrappers for shells such as PowerShell and Windows Command Prompt. `CliInvoke.Specializations` versions 2.2.0 through 2.8.4, 2.9.0 through 2.9.3, 2.10.0 through 2.10.4, 3.0.0-alpha.1 through 3.0.0-alpha.4, and 3.0.0-alpha.8 through 3.0.0-alpha.10, as well as `AlastairLundy.CliInvoke.Specializations` versions 1.0.0-rc.1 through 1.6.1.1, contain an OS command injection vulnerability in their PowerShell and Cmd wrappers. The wrappers pass a caller-controlled target and arguments to `pwsh -Command` or `cmd /c` using a single `ProcessStartInfo.Arguments` string, allowing a double quote in untrusted input to break operating-system-level quoting and cause the shell to execute an additional command with the host process's privileges. The vulnerability is patched in `CliInvoke.Specializations` versions 2.8.5, 2.9.4, 2.10.5, and 3.0.0-beta.1, and in `AlastairLundy.CliInvoke.Specializations` version 2.0.2. No complete workaround is available; users unable to upgrade should reject or remove double quotes from target paths and arguments, additionally reject shell metacharacters in versions 2.2.0 through 2.9.2 and 3.0.0-alpha.1 through 3.0.0-alpha.4, or bypass the PowerShell and Cmd wrappers and invoke target processes directly when handling untrusted input.
CliInvoke is a .NET library for invoking command-line programs, and its `CliInvoke.Specializations` packages provide specialized wrappers for shells such as PowerShell and Windows Command Prompt. `CliInvoke.Specializations` versions 2.2.0 through 2.8.4, 2.9.0 through 2.9.3, 2.10.0 through 2.10.4, 3.0.0-alpha.1 through 3.0.0-alpha.4, and 3.0.0-alpha.8 through 3.0.0-alpha.10, as well as `AlastairLundy.CliInvoke.Specializations` versions 1.0.0-rc.1 through 1.6.1.1, contain an OS command injection vulnerability in their PowerShell and Cmd wrappers. The wrappers pass a caller-controlled target and arguments to `pwsh -Command` or `cmd /c` using a single `ProcessStartInfo.Arguments` string, allowing a double quote in untrusted input to break operating-system-level quoting and cause the shell to execute an additional command with the host process's privileges. The vulnerability is patched in `CliInvoke.Specializations` versions 2.8.5, 2.9.4, 2.10.5, and 3.0.0-beta.1, and in `AlastairLundy.CliInvoke.Specializations` version 2.0.2. No complete workaround is available; users unable to upgrade should reject or remove double quotes from target paths and arguments, additionally reject shell metacharacters in versions 2.2.0 through 2.9.2 and 3.0.0-alpha.1 through 3.0.0-alpha.4, or bypass the PowerShell and Cmd wrappers and invoke target processes directly when handling untrusted input.
### Impact
An OS command injection vulnerability exists in the PowerShell and Cmd shell wrappers provided by the `CliInvoke.Specializations` package (the `PowershellProcessInvoker`/`CmdProcessInvoker` invokers, and the `UsePowerShell`/`UseCmd` middleware in v3 pre-release versions).
The wrappers re-run a caller-supplied target and arguments inside a shell command (`pwsh -Command ...` / `cmd /c ...`). In affected versions the wrapped command was delivered to the operating system as a single `ProcessStartInfo.Arguments` string. The OS command-line parser re-tokenizes that string before the shell parses it, so a double quote (`"`) in the target or arguments breaks OS-level quoting and lets the wrapped shell reassemble a second, unintended command.
An attacker could exploit this to execute arbitrary commands with the privileges of the host process.
### Patches
The Specializations Packages now deliver the command via `ProcessStartInfo.ArgumentList` (natively where supported, and polyfilled in older TFMs), so that the operating system passes argv verbatim and only the shell parses the command once.
Upgrade to:
- **2.8.5** (2.8.x line)
- **2.9.4** (2.9.x line)
- **2.10.5** (2.10.x line)
- **3.0.0-beta.1** (3.x pre-release line)
### Workarounds
No complete workaround is available. Until upgraded:
- Reject or strip `"` from any target path or argument passed to the PowerShell/Cmd wrappers. On 2.2.0 – 2.9.2 and 3.0.0-alpha.1 – alpha.4, also reject shell metacharacters (`;`, `|`, `&`, `$`, backtick, parentheses).
- Alternatively, bypass the wrappers for untrusted input and invoke the target process directly so that no second shell parse of the data occurs.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Sep 25, 2026, 7:53:56 PM
dateUpdated: Sep 30, 2026, 12:06:47 AM
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Deferred
Weakness classifications: CWE-78
Original publisher date fields
published: 2026-09-25T20:17:05.990
lastModified: 2026-09-30T19:57:08.043
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.