Unchecked low-level call

Severity: High ID: unchecked-call

Flags low-level calls (call, delegatecall, staticcall, callcode) whose success return value is ignored.

What it does

Warns when the boolean returned by a low-level call is discarded — either because the return value is not assigned or because only the bytes memory payload is used.

Why is this bad?

Low-level calls do not revert when the callee fails; they silently return false. Ignoring the success flag means a failed call is indistinguishable from a successful one, leading to bugs where state is updated on the assumption that an external interaction succeeded.

Example

Bad

target.call(data);                          // success ignored
(, bytes memory ret) = target.call(data);   // only payload kept

Good

(bool ok, ) = target.call(data);
require(ok, "call failed");