diff --git a/projects/packages/waf/changelog/fix-protect-174-cli-cron-403 b/projects/packages/waf/changelog/fix-protect-174-cli-cron-403
new file mode 100644
index 000000000000..5118259a2c0c
--- /dev/null
+++ b/projects/packages/waf/changelog/fix-protect-174-cli-cron-403
@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+WAF: Skip rule evaluation when there is no HTTP request (e.g. server-side cron executed via a PHP CLI wrapper), preventing false-positive 403 blocks from rule 911100.
diff --git a/projects/packages/waf/src/class-waf-runner.php b/projects/packages/waf/src/class-waf-runner.php
index 929f118cd7cd..2d8d3eda16f8 100644
--- a/projects/packages/waf/src/class-waf-runner.php
+++ b/projects/packages/waf/src/class-waf-runner.php
@@ -238,8 +238,12 @@ public static function run() {
 		// like PHP's prepend_file setting (yay!).
 		define( 'JETPACK_WAF_RUN', defined( 'ABSPATH' ) ? 'plugin' : 'preload' );
 
-		// if the WAF is being run before a command line script, don't try to execute rules (there's no request).
-		if ( PHP_SAPI === 'cli' ) {
+		// If the WAF is being run before a command line script, or in any other non-HTTP
+		// context (e.g. server-side cron executed via a PHP wrapper that does not report
+		// PHP_SAPI as 'cli'), there is no HTTP request to evaluate. Skip rule execution so
+		// HTTP-specific rules (e.g. rule 911100, which checks the request method) don't
+		// produce a false-positive 403 block.
+		if ( PHP_SAPI === 'cli' || ! isset( $_SERVER['REQUEST_METHOD'] ) ) {
 			return;
 		}
 
diff --git a/projects/packages/waf/tests/php/unit/WafRunnerTest.php b/projects/packages/waf/tests/php/unit/WafRunnerTest.php
index 660e4b3f93e4..7423a420039b 100644
--- a/projects/packages/waf/tests/php/unit/WafRunnerTest.php
+++ b/projects/packages/waf/tests/php/unit/WafRunnerTest.php
@@ -7,6 +7,7 @@
 
 use Automattic\Jetpack\Waf\Waf_Constants;
 use Automattic\Jetpack\Waf\Waf_Runner;
+use PHPUnit\Framework\Attributes\PreserveGlobalState;
 use PHPUnit\Framework\Attributes\RunInSeparateProcess;
 
 /**
@@ -51,4 +52,50 @@ public function testRunSetsConstants() {
 		$this->assertSame( '/pseudo/dir/jetpack-waf', JETPACK_WAF_DIR );
 		$this->assertSame( '/pseudo/dir/../wp-config.php', JETPACK_WAF_WPCONFIG );
 	}
+
+	/**
+	 * Test that run does not evaluate rules when there is no HTTP request method.
+	 *
+	 * Reproduces PROTECT-174: when wp-cron.php is executed directly (e.g. via a PHP
+	 * wrapper for a server-side cron) there is no HTTP context, so REQUEST_METHOD is
+	 * absent. The WAF must skip rule evaluation in that case so that HTTP-specific
+	 * rules (e.g. rule 911100, which checks the request method) don't fire a
+	 * false-positive 403.
+	 *
+	 * @runInSeparateProcess
+	 * @preserveGlobalState disabled
+	 */
+	#[RunInSeparateProcess]
+	#[PreserveGlobalState( false )]
+	public function testRunSkipsRulesWhenRequestMethodIsAbsent() {
+		define( 'ABSPATH', '/pseudo' );
+		define( 'WP_CONTENT_DIR', '/pseudo/dir' );
+
+		// Simulate a non-HTTP execution context: no REQUEST_METHOD present.
+		unset( $_SERVER['REQUEST_METHOD'] );
+
+		// Point the WAF at a rules file that would set a flag if it were ever included.
+		$rules_dir  = sys_get_temp_dir() . '/jetpack-waf-test-' . uniqid();
+		$rules_file = $rules_dir . '/rules.php';
+		mkdir( $rules_dir );
+		file_put_contents( $rules_file, '<?php define( "JETPACK_WAF_RULES_EXECUTED", true );' );
+
+		define( 'JETPACK_WAF_DIR', $rules_dir );
+		define( 'JETPACK_WAF_WPCONFIG', '/pseudo/wp-config.php' );
+		define( 'JETPACK_WAF_ENTRYPOINT', 'rules.php' );
+		define( 'JETPACK_WAF_MODE', 'normal' );
+
+		try {
+			Waf_Runner::run();
+
+			// run() reached the guard (the run-context constant is set before it)...
+			$this->assertTrue( defined( 'JETPACK_WAF_RUN' ), 'Waf_Runner::run() should have started executing.' );
+			// ...but returned early without ever including the rules file.
+			$this->assertFalse( defined( 'JETPACK_WAF_RULES_EXECUTED' ), 'WAF rules must not be evaluated when there is no HTTP request method.' );
+		} finally {
+			// Clean up, even if an assertion fails.
+			unlink( $rules_file );
+			rmdir( $rules_dir );
+		}
+	}
 }