cargo.exe from Rust 1.97.1 is blocked by Windows 11 Smart App Control, while 1.96.0 works

Summary

After upgrading from Rust 1.96.0 to 1.97.1 on Windows 11, cargo.exe is blocked by Windows Smart App Control.

Downgrading back to Rust 1.96.0 immediately fixes the problem.

Environment

• Windows 11
• Smart App Control: On
• rustup: 1.29.0
• Rust 1.97.1
• x86_64-pc-windows-msvc

Reproduction

Install Rust 1.97.1:

rustup update
cargo --version


Result:

error: command failed: 'cargo': Application Control policy has blocked this file. (os error 4551)

Downgrade:

rustup toolchain install 1.96.0
rustup default 1.96.0
cargo --version

Result:

cargo 1.96.0 (...)


Additional information
rustup.exe works.
rustc.exe works.
Only cargo.exe is blocked.

Windows Code Integrity Event Log:

Code Integrity determined that a process
(\Users\...\cargo.exe)
attempted to load
(\Users\...\toolchains\stable-x86_64-pc-windows-msvc\bin\cargo.exe)
that did not meet the Enterprise signing level requirements
or violated code integrity policy.

Smart App Control state:

On

Start with the reported cargo.exe entry point and reproduce cargo --version on Windows 11 with Smart App Control enabled, comparing Rust 1.97.1 against 1.96.0. Review the Windows Code Integrity Event Log and the rustup-installed toolchain artifacts; done means cargo.exe from 1.97.1 runs successfully under the reported policy without regressing rustup.exe or rustc.exe.