README.md

@@ -162,11 +162,8 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     github-server-url: ''
 
     # Required to check out fork pull request code from a workflow triggered by
-    # `pull_request_target` or `workflow_run`. These workflows run with the base
+    # `pull_request_target` or `workflow_run`. See [Pwn Requests](todo:need-link) for
-    # repository's GITHUB_TOKEN, secrets, default-branch cache scope, and runner
+    # the risks. Set to `true` only after reviewing the risks.
-    # access; fetching and executing a fork's code in that trusted context commonly
-    # leads to "pwn request" vulnerabilities. Set to `true` only after reviewing the
-    # risks at https://gh.io/securely-using-pull_request_target.
     # Default: false
     allow-unsafe-pr-checkout: ''
 ```

action.yml

@@ -101,11 +101,8 @@ inputs:
   allow-unsafe-pr-checkout:
     description: >
       Required to check out fork pull request code from a workflow triggered by
-      `pull_request_target` or `workflow_run`. These workflows run with the
+      `pull_request_target` or `workflow_run`. See [Pwn Requests](todo:need-link)
-      base repository's GITHUB_TOKEN, secrets, default-branch cache scope, and
+      for the risks. Set to `true` only after reviewing the risks.
-      runner access; fetching and executing a fork's code in that trusted
-      context commonly leads to "pwn request" vulnerabilities. Set to `true`
-      only after reviewing the risks at https://gh.io/securely-using-pull_request_target.
     default: false
 outputs:
   ref:

dist/index.js

@@ -2832,9 +2832,8 @@ function assertSafePrCheckout(input) {
     }
     throw new Error(`Refusing to check out fork pull request code from a '${eventName}' workflow. ` +
         `This workflow runs with the base repository's GITHUB_TOKEN, secrets, default-branch ` +
-        `cache scope, and runner access. Fetching and executing a fork's code in that trusted ` +
+        `cache scope, and runner access. Fetching fork's code in that trusted context is a ` +
-        `context commonly leads to "pwn request" vulnerabilities. To opt in after reviewing ` +
+        `"pwn request" supply-chain attack pattern. To opt in after reviewing the risk, set ` +
-        `the risks at https://gh.io/securely-using-pull_request_target, set ` +
         `'allow-unsafe-pr-checkout: true' on the actions/checkout step.`);
 }
 function pushIfSha(target, value) {

src/unsafe-pr-checkout-helper.ts

@@ -74,9 +74,8 @@ export function assertSafePrCheckout(input: IUnsafePrCheckoutInput): void {
   throw new Error(
     `Refusing to check out fork pull request code from a '${eventName}' workflow. ` +
       `This workflow runs with the base repository's GITHUB_TOKEN, secrets, default-branch ` +
-      `cache scope, and runner access. Fetching and executing a fork's code in that trusted ` +
+      `cache scope, and runner access. Fetching fork's code in that trusted context is a ` +
-      `context commonly leads to "pwn request" vulnerabilities. To opt in after reviewing ` +
+      `"pwn request" supply-chain attack pattern. To opt in after reviewing the risk, set ` +
-      `the risks at https://gh.io/securely-using-pull_request_target, set ` +
       `'allow-unsafe-pr-checkout: true' on the actions/checkout step.`
   )
 }