diff --git a/ext/mbstring/libmbfl/mbfl/mbfilter.c b/ext/mbstring/libmbfl/mbfl/mbfilter.c
index d25abb63369e4..4820f15e214ce 100644
--- a/ext/mbstring/libmbfl/mbfl/mbfilter.c
+++ b/ext/mbstring/libmbfl/mbfl/mbfilter.c
@@ -1276,6 +1276,7 @@ mbfl_strcut(
 			bk = _bk;
 		}
 
+		decoder->illegal_mode = MBFL_OUTPUTFILTER_ILLEGAL_MODE_NONE;
 		(*encoder->filter_flush)(encoder);
 
 		if (bk.decoder.filter_dtor)
diff --git a/ext/mbstring/tests/gh9535.phpt b/ext/mbstring/tests/gh9535.phpt
new file mode 100644
index 0000000000000..d67b6a0863063
--- /dev/null
+++ b/ext/mbstring/tests/gh9535.phpt
@@ -0,0 +1,210 @@
+--TEST--
+GH-9535 (mb_strcut(): The behavior of mb_strcut in mbstring has been changed in PHP8.1)
+--EXTENSIONS--
+mbstring
+--FILE--
+<?php
+$encodings = [
+	'BASE64',
+	'HTML-ENTITIES',
+	'Quoted-Printable',
+    'UTF-16',
+    'UTF-16BE',
+    'UTF-16LE',
+    'UTF-7',
+    'UTF7-IMAP',
+    'JIS',
+    'ISO-2022-JP',
+    'ISO-2022-JP-MS',
+    'GB18030',
+    'HZ',
+    'ISO-2022-KR',
+    'ISO-2022-JP-2004',
+    'ISO-2022-JP-MOBILE#KDDI',
+    'CP50220',
+    'CP50221',
+    'CP50222',
+];
+
+$input = '宛如繁星般宛如皎月般';
+$bytes_length = 15;
+foreach($encodings as $encoding) {
+    $converted_str = mb_convert_encoding($input, $encoding, mb_internal_encoding());
+    $cut_str = mb_strcut($converted_str, 0, $bytes_length, $encoding);
+    $reconverted_str = mb_convert_encoding($cut_str, mb_internal_encoding(), $encoding);
+    echo $encoding.': '.$reconverted_str.PHP_EOL;
+}
+
+echo PHP_EOL;
+
+$input = '星のように月のように';
+$bytes_length = 20;
+foreach($encodings as $encoding) {
+    $converted_str = mb_convert_encoding($input, $encoding, mb_internal_encoding());
+    $cut_str = mb_strcut($converted_str, 0, $bytes_length, $encoding);
+    $reconverted_str = mb_convert_encoding($cut_str, mb_internal_encoding(), $encoding);
+    echo $encoding.': '.$reconverted_str.PHP_EOL;
+}
+
+echo PHP_EOL;
+
+$input = 'あaいb';
+$bytes_length = 10;
+foreach($encodings as $encoding) {
+    $converted_str = mb_convert_encoding($input, $encoding, mb_internal_encoding());
+    $cut_str = mb_strcut($converted_str, 0, $bytes_length, $encoding);
+    $reconverted_str = mb_convert_encoding($cut_str, mb_internal_encoding(), $encoding);
+    echo $encoding.': '.$reconverted_str.PHP_EOL;
+}
+
+echo PHP_EOL;
+
+$input = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA';
+$bytes_length = 10;
+foreach($encodings as $encoding) {
+    $converted_str = mb_convert_encoding($input, $encoding, mb_internal_encoding());
+    $cut_str = mb_strcut($converted_str, 0, $bytes_length, $encoding);
+    $reconverted_str = mb_convert_encoding($cut_str, mb_internal_encoding(), $encoding);
+    echo $encoding.': '.$reconverted_str.PHP_EOL;
+}
+
+echo PHP_EOL;
+
+$input = '???';
+$bytes_length = 2;
+foreach($encodings as $encoding) {
+    $converted_str = mb_convert_encoding($input, $encoding, mb_internal_encoding());
+    $cut_str = mb_strcut($converted_str, 0, $bytes_length, $encoding);
+    $reconverted_str = mb_convert_encoding($cut_str, mb_internal_encoding(), $encoding);
+    echo $encoding.': '.$reconverted_str.PHP_EOL;
+}
+
+echo PHP_EOL;
+
+foreach($encodings as $encoding) {
+    var_dump(mb_strcut($input, 0, $bytes_length, $encoding));
+}
+
+?>
+--XFAIL--
+Discussion: https://github.com/php/php-src/pull/9562
+--EXPECTF--
+BASE64: 宛如繁
+HTML-ENTITIES: 宛&#22914
+Quoted-Printable: %s
+UTF-16: 宛如繁星般宛如
+UTF-16BE: 宛如繁星般宛如
+UTF-16LE: 宛如繁星般宛如
+UTF-7: 宛如繁星
+UTF7-IMAP: 宛如繁星
+JIS: 宛如繁星般
+ISO-2022-JP: 宛如繁星般
+ISO-2022-JP-MS: 宛如繁星
+GB18030: 宛如繁星般宛如
+HZ: 宛如繁星般
+ISO-2022-KR: 宛如繁星
+ISO-2022-JP-2004: 宛如繁星
+ISO-2022-JP-MOBILE#KDDI: 宛如繁星
+CP50220: 宛如繁星
+CP50221: 宛如繁星
+CP50222: 宛如繁星
+
+BASE64: 星のように
+HTML-ENTITIES: 星の&#12
+Quoted-Printable: 星の
+UTF-16: 星のように月のように
+UTF-16BE: 星のように月のように
+UTF-16LE: 星のように月のように
+UTF-7: 星のように月
+UTF7-IMAP: 星のように月
+JIS: 星のように月の
+ISO-2022-JP: 星のように月の
+ISO-2022-JP-MS: 星のように月の
+GB18030: 星のように月のように
+HZ: 星のように月のよ
+ISO-2022-KR: 星のように月の
+ISO-2022-JP-2004: 星のように月の
+ISO-2022-JP-MOBILE#KDDI: 星のように月の
+CP50220: 星のように月の
+CP50221: 星のように月の
+CP50222: 星のように月の
+
+BASE64: %s
+HTML-ENTITIES: あa&
+Quoted-Printable: あa
+UTF-16: あaいb
+UTF-16BE: あaいb
+UTF-16LE: あaいb
+UTF-7: あa
+UTF7-IMAP: あa
+JIS: あa
+ISO-2022-JP: あa
+ISO-2022-JP-MS: あa
+GB18030: あaいb
+HZ: あa
+ISO-2022-KR: あa
+ISO-2022-JP-2004: あa
+ISO-2022-JP-MOBILE#KDDI: あa
+CP50220: あa
+CP50221: あa
+CP50222: あa
+
+BASE64: AAAAAA
+HTML-ENTITIES: AAAAAAAAAA
+Quoted-Printable: AAAAAAAAAA
+UTF-16: AAAAA
+UTF-16BE: AAAAA
+UTF-16LE: AAAAA
+UTF-7: AAAAAAAAAA
+UTF7-IMAP: AAAAAAAAAA
+JIS: AAAAAAAAAA
+ISO-2022-JP: AAAAAAAAAA
+ISO-2022-JP-MS: AAAAAAAAAA
+GB18030: AAAAAAAAAA
+HZ: AAAAAAAAAA
+ISO-2022-KR: AAAAAAAAAA
+ISO-2022-JP-2004: AAAAAAAAAA
+ISO-2022-JP-MOBILE#KDDI: AAAAAAAAAA
+CP50220: AAAAAAAAAA
+CP50221: AAAAAAAAAA
+CP50222: AAAAAAAAAA
+
+BASE64:%s
+HTML-ENTITIES: ??
+Quoted-Printable: ??
+UTF-16: ?
+UTF-16BE: ?
+UTF-16LE: ?
+UTF-7: ??
+UTF7-IMAP: ??
+JIS: ??
+ISO-2022-JP: ??
+ISO-2022-JP-MS: ??
+GB18030: ??
+HZ: ??
+ISO-2022-KR: ??
+ISO-2022-JP-2004: ??
+ISO-2022-JP-MOBILE#KDDI: ??
+CP50220: ??
+CP50221: ??
+CP50222: ??
+
+string(0) ""
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"
+string(2) "??"