diff --git a/wordpress.org/public_html/wp-content/plugins/plugin-directory/cli/class-import.php b/wordpress.org/public_html/wp-content/plugins/plugin-directory/cli/class-import.php
index 1abbec62b1..70234d289f 100644
--- a/wordpress.org/public_html/wp-content/plugins/plugin-directory/cli/class-import.php
+++ b/wordpress.org/public_html/wp-content/plugins/plugin-directory/cli/class-import.php
@@ -196,6 +196,8 @@ public function import_from_svn( $plugin_slug, $svn_changed_tags = array( 'trunk
 			];
 		}
 
+		$this->warnings = array_merge( $this->warnings, self::requires_header_warnings( $headers, $readme ) );
+
 		/*
 		 * Check to see if the plugin is using the `Update URI` header.
 		 *
@@ -1496,6 +1498,55 @@ public static function version_matches_tag( $version, $tag ) {
 		return version_compare( $normalized_tag, $normalized_version, '==' );
 	}
 
+	/**
+	 * Check the plugin's Requires at least and Requires PHP headers.
+	 *
+	 * WordPress enforces these headers from the main plugin file, so unlike the readme fields
+	 * they can't be ignored when invalid. Warn when a header isn't a valid version, is higher
+	 * than the readme allows, or disagrees with the readme.
+	 *
+	 * @param object $headers The plugin headers, with `RequiresWP` and `RequiresPHP` properties.
+	 * @param object $readme  The parsed readme, with `requires` and `requires_php` properties.
+	 * @return array Import warnings, keyed by warning code.
+	 */
+	public static function requires_header_warnings( $headers, $readme ) {
+		$warnings = [];
+
+		// `6.0` and `6.0.0` are the same requirement.
+		$normalize = static function ( $v ) {
+			return preg_replace( '/(\.0)+$/', '', $v );
+		};
+
+		$stable_branch = defined( 'WP_CORE_STABLE_BRANCH' ) ? WP_CORE_STABLE_BRANCH : $GLOBALS['wp_version'];
+
+		$requires = $headers->RequiresWP ?? ''; // phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase -- Plugin header key.
+		if ( $requires ) {
+			// Same rules the readme parser applies to its Requires at least field.
+			if ( ! preg_match( '!^\d+\.\d(\.\d+)?$!', $requires ) || (float) $requires > round( (float) $stable_branch + 0.1, 1 ) ) {
+				$warnings['plugin_requires_header_invalid'] = $requires;
+			} elseif ( ! empty( $readme->requires ) && $normalize( $requires ) !== $normalize( $readme->requires ) ) {
+				$warnings['requires_header_mismatch'] = [
+					'plugin' => $requires,
+					'readme' => $readme->requires,
+				];
+			}
+		}
+
+		$requires_php = $headers->RequiresPHP ?? ''; // phpcs:ignore WordPress.NamingConventions.ValidVariableName.UsedPropertyNotSnakeCase -- Plugin header key.
+		if ( $requires_php ) {
+			if ( ! preg_match( '!^\d+(\.\d+){1,2}$!', $requires_php ) ) {
+				$warnings['plugin_requires_php_header_invalid'] = $requires_php;
+			} elseif ( ! empty( $readme->requires_php ) && $normalize( $requires_php ) !== $normalize( $readme->requires_php ) ) {
+				$warnings['requires_php_header_mismatch'] = [
+					'plugin' => $requires_php,
+					'readme' => $readme->requires_php,
+				];
+			}
+		}
+
+		return $warnings;
+	}
+
 	/**
 	 * Add support for additional plugin headers prior to WordPress supporting it.
 	 *
diff --git a/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-parser.php b/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-parser.php
index 3fd4b782fe..84b88b7e4d 100644
--- a/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-parser.php
+++ b/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-parser.php
@@ -867,7 +867,7 @@ protected function sanitize_requires_version( $version ) {
 				// x.y or x.y.z
 				! preg_match( '!^\d+\.\d(\.\d+)?$!', $version ) ||
 				// Allow plugins to mark themselves as requireing Stable+0.1 (trunk/master) but not higher
-				defined( 'WP_CORE_STABLE_BRANCH' ) && ( (float)$version > (float)WP_CORE_STABLE_BRANCH+0.1 )
+				( defined( 'WP_CORE_STABLE_BRANCH' ) && (float) $version > round( (float) WP_CORE_STABLE_BRANCH + 0.1, 1 ) )
 			 ) {
 				$this->warnings['requires_header_ignored'] = true;
 				// Ignore the readme value.
diff --git a/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-validator.php b/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-validator.php
index 70d73c5fd6..04ffe23865 100644
--- a/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-validator.php
+++ b/wordpress.org/public_html/wp-content/plugins/plugin-directory/readme/class-validator.php
@@ -335,6 +335,36 @@ public function translate_code_to_message( $error_code, $data = false ) {
 					__( 'The %s field is missing. It should be defined here, or in your main plugin file.', 'wporg-plugins' ),
 					'<code>Requires PHP</code>'
 				);
+			case 'plugin_requires_header_invalid':
+				$latest_wordpress_version = defined( 'WP_CORE_STABLE_BRANCH' ) ? WP_CORE_STABLE_BRANCH : '6.5';
+
+				return sprintf(
+					/* translators: 1: plugin header tag; 2: the header value; 3: Example version 5.0. 4: Example version 4.9. */
+					__( 'The %1$s header in your main plugin file (%2$s) is not a valid WordPress version. WordPress checks this header before activating your plugin, so it should only contain a WordPress version such as %3$s or %4$s.', 'wporg-plugins' ),
+					'<code>Requires at least</code>',
+					'<code>' . esc_html( $data ) . '</code>',
+					'<code>' . number_format( $latest_wordpress_version, 1 ) . '</code>',
+					'<code>' . number_format( $latest_wordpress_version - 0.1, 1 ) . '</code>'
+				);
+			case 'plugin_requires_php_header_invalid':
+				global $required_php_version; // WP wp-includes/version.php.
+				return sprintf(
+					/* translators: 1: plugin header tag; 2: the header value; 3: Example version 7.0. 4: Example version 8.2. */
+					__( 'The %1$s header in your main plugin file (%2$s) is not a valid PHP version. WordPress checks this header before activating your plugin, so it should only contain a PHP version such as %3$s or %4$s.', 'wporg-plugins' ),
+					'<code>Requires PHP</code>',
+					'<code>' . esc_html( $data ) . '</code>',
+					'<code>' . esc_html( $required_php_version ?? '7.0' ) . '</code>',
+					'<code>8.2</code>'
+				);
+			case 'requires_header_mismatch':
+			case 'requires_php_header_mismatch':
+				return sprintf(
+					/* translators: 1: plugin header tag; 2: the value in the main plugin file; 3: the value in the readme. */
+					__( 'The %1$s header in your main plugin file (%2$s) does not match the one in your readme (%3$s). The value from your main plugin file is used, so update your readme to match.', 'wporg-plugins' ),
+					'<code>' . ( 'requires_header_mismatch' === $error_code ? 'Requires at least' : 'Requires PHP' ) . '</code>',
+					'<code>' . esc_html( is_array( $data ) ? ( $data['plugin'] ?? '' ) : '' ) . '</code>',
+					'<code>' . esc_html( is_array( $data ) ? ( $data['readme'] ?? '' ) : '' ) . '</code>'
+				);
 			case 'stable_tag_invalid':
 				return sprintf(
 					/* translators: 1: 'Stable tag', 2: /trunk/ SVN directory */
diff --git a/wordpress.org/public_html/wp-content/plugins/plugin-directory/tests/Import_Requires_Header_Warnings_Test.php b/wordpress.org/public_html/wp-content/plugins/plugin-directory/tests/Import_Requires_Header_Warnings_Test.php
new file mode 100644
index 0000000000..c3b1f77c16
--- /dev/null
+++ b/wordpress.org/public_html/wp-content/plugins/plugin-directory/tests/Import_Requires_Header_Warnings_Test.php
@@ -0,0 +1,114 @@
+<?php
+/**
+ * Tests for Import::requires_header_warnings().
+ *
+ * @package WordPressdotorg\Plugin_Directory\Tests
+ */
+
+declare( strict_types = 1 );
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\TestCase;
+use WordPressdotorg\Plugin_Directory\CLI\Import;
+
+/**
+ * Covers the import warnings for the Requires at least and Requires PHP plugin headers.
+ *
+ * @group import
+ */
+#[Group( 'import' )]
+class Import_Requires_Header_Warnings_Test extends TestCase {
+
+	/**
+	 * The plugin headers are checked on their own and against the readme.
+	 *
+	 * @dataProvider headers_provider
+	 *
+	 * @param array $headers  The RequiresWP and RequiresPHP plugin headers.
+	 * @param array $readme   The readme's requires and requires_php fields.
+	 * @param array $expected The expected warnings.
+	 * @return void
+	 */
+	#[DataProvider( 'headers_provider' )]
+	public function test_requires_header_warnings( array $headers, array $readme, array $expected ): void {
+		$this->assertSame( $expected, Import::requires_header_warnings( (object) $headers, (object) $readme ) );
+	}
+
+	/**
+	 * Supplies plugin headers, readme fields, and the warnings they should produce.
+	 *
+	 * @return array<string, array<int, array>>
+	 */
+	public static function headers_provider(): array {
+		return array(
+			'matching, with trailing .0'  => array(
+				array(
+					'RequiresWP'  => '6.0',
+					'RequiresPHP' => '7.4',
+				),
+				array(
+					'requires'     => '6.0.0',
+					'requires_php' => '7.4',
+				),
+				array(),
+			),
+			'no readme fields to compare' => array(
+				array(
+					'RequiresWP'  => '6.0',
+					'RequiresPHP' => '7.4',
+				),
+				array(
+					'requires'     => '',
+					'requires_php' => '',
+				),
+				array(),
+			),
+			'header newer than trunk'     => array(
+				array(
+					'RequiresWP'  => '99.0',
+					'RequiresPHP' => '',
+				),
+				array(
+					'requires'     => '6.0',
+					'requires_php' => '',
+				),
+				array( 'plugin_requires_header_invalid' => '99.0' ),
+			),
+			'headers not versions'        => array(
+				array(
+					'RequiresWP'  => '6.0-beta',
+					'RequiresPHP' => '8',
+				),
+				array(
+					'requires'     => '',
+					'requires_php' => '',
+				),
+				array(
+					'plugin_requires_header_invalid'     => '6.0-beta',
+					'plugin_requires_php_header_invalid' => '8',
+				),
+			),
+			'headers differ from readme'  => array(
+				array(
+					'RequiresWP'  => '6.2',
+					'RequiresPHP' => '8.0',
+				),
+				array(
+					'requires'     => '6.0',
+					'requires_php' => '7.4',
+				),
+				array(
+					'requires_header_mismatch'     => array(
+						'plugin' => '6.2',
+						'readme' => '6.0',
+					),
+					'requires_php_header_mismatch' => array(
+						'plugin' => '8.0',
+						'readme' => '7.4',
+					),
+				),
+			),
+		);
+	}
+}