diff --git a/EXTENSIONS b/EXTENSIONS
index 2eec7726c12c4..8da09aed5392a 100644
--- a/EXTENSIONS
+++ b/EXTENSIONS
@@ -372,8 +372,8 @@ STATUS:              Working
 EXTENSION:           mbstring
 PRIMARY MAINTAINER:  Rui Hirokawa <hirokawa@php.net> (2001 - 2013)
                      Nikita Popov <nikic@php.net> (2017 - 2020)
-                     Alex Dowad <alexinbeijing@gmail.com> (2021 - 2024)
-                     Yuya Hamada <youkidearitai@gmail.com> (2024 - 2024)
+                     Alex Dowad <alexinbeijing@gmail.com> (2021 - 2026)
+                     Yuya Hamada <youkidearitai@gmail.com> (2024 - 2026)
 MAINTENANCE:         Maintained
 STATUS:              Working
 -------------------------------------------------------------------------------
diff --git a/ext/bz2/bz2.c b/ext/bz2/bz2.c
index a8153d7d11938..91e694f58f465 100644
--- a/ext/bz2/bz2.c
+++ b/ext/bz2/bz2.c
@@ -537,18 +537,17 @@ PHP_FUNCTION(bzdecompress)
 	while ((error = BZ2_bzDecompress(&bzs)) == BZ_OK && bzs.avail_in > 0) {
 		/* compression is better then 2:1, need to allocate more memory */
 		bzs.avail_out = source_len;
-		size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
+		size = (((uint64_t) bzs.total_out_hi32) << 32U) + bzs.total_out_lo32;
 		if (UNEXPECTED(size > SIZE_MAX)) {
 			/* no reason to continue if we're going to drop it anyway */
 			break;
 		}
-
 		dest = zend_string_safe_realloc(dest, 1, bzs.avail_out+1, (size_t) size, 0);
 		bzs.next_out = ZSTR_VAL(dest) + size;
 	}
 
 	if (error == BZ_STREAM_END || error == BZ_OK) {
-		size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32;
+		size = (((uint64_t) bzs.total_out_hi32) << 32U) + bzs.total_out_lo32;
 		if (UNEXPECTED(size > SIZE_MAX)) {
 			php_error_docref(NULL, E_WARNING, "Decompressed size too big, max is %zu", SIZE_MAX);
 			zend_string_efree(dest);
diff --git a/ext/bz2/tests/gh20807.phpt b/ext/bz2/tests/gh20807.phpt
new file mode 100644
index 0000000000000..8d1e0cb40e4fd
--- /dev/null
+++ b/ext/bz2/tests/gh20807.phpt
@@ -0,0 +1,19 @@
+--TEST--
+Truncation of total output size causing erroneous size and data
+--EXTENSIONS--
+bz2
+--INI--
+memory_limit=-1
+--SKIPIF--
+<?php
+if (!getenv('RUN_RESOURCE_HEAVY_TESTS')) die('skip resource-heavy test');
+if (getenv("SKIP_SLOW_TESTS")) die('skip slow test');
+if (PHP_OS === 'FreeBSD') die('skip Worker does not handle OOM gracefully');
+if (PHP_INT_SIZE !== 8) die('skip Only for 64-bit systems');
+?>
+--FILE--
+<?php
+var_dump(sha1(bzdecompress(base64_decode("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"))));
+?>
+--EXPECT--
+string(40) "d4b5e52ed34a774fa645f94369b0c61375436d30"
diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c
index 7b07c8240be04..32ab6b0e5090b 100644
--- a/ext/pcre/php_pcre.c
+++ b/ext/pcre/php_pcre.c
@@ -1167,6 +1167,7 @@ PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str,
 	HashTable		*marks = NULL;		/* Array of marks for PREG_PATTERN_ORDER */
 	pcre2_match_data *match_data;
 	PCRE2_SIZE		 start_offset2, orig_start_offset;
+	bool old_mdata_used;
 
 	char *subject = ZSTR_VAL(subject_str);
 	size_t subject_len = ZSTR_LEN(subject_str);
@@ -1236,7 +1237,9 @@ PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str,
 	matched = 0;
 	PCRE_G(error_code) = PHP_PCRE_NO_ERROR;
 
-	if (!mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+	old_mdata_used = mdata_used;
+	if (!old_mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+		mdata_used = true;
 		match_data = mdata;
 	} else {
 		match_data = pcre2_match_data_create_from_pattern(pce->re, PCRE_G(gctx_zmm));
@@ -1433,6 +1436,7 @@ PHPAPI void php_pcre_match_impl(pcre_cache_entry *pce, zend_string *subject_str,
 	if (match_data != mdata) {
 		pcre2_match_data_free(match_data);
 	}
+	mdata_used = old_mdata_used;
 
 	/* Add the match sets to the output array and clean up */
 	if (match_sets) {
@@ -1629,6 +1633,7 @@ PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *su
 	size_t			result_len; 		/* Length of result */
 	zend_string		*result;			/* Result of replacement */
 	pcre2_match_data *match_data;
+	bool old_mdata_used;
 
 	/* Calculate the size of the offsets array, and allocate memory for it. */
 	num_subpats = pce->capture_count + 1;
@@ -1642,7 +1647,9 @@ PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *su
 	result_len = 0;
 	PCRE_G(error_code) = PHP_PCRE_NO_ERROR;
 
-	if (!mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+	old_mdata_used = mdata_used;
+	if (!old_mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+		mdata_used = true;
 		match_data = mdata;
 	} else {
 		match_data = pcre2_match_data_create_from_pattern(pce->re, PCRE_G(gctx_zmm));
@@ -1844,6 +1851,7 @@ PHPAPI zend_string *php_pcre_replace_impl(pcre_cache_entry *pce, zend_string *su
 	if (match_data != mdata) {
 		pcre2_match_data_free(match_data);
 	}
+	mdata_used = old_mdata_used;
 
 	return result;
 }
@@ -2569,6 +2577,7 @@ PHPAPI void php_pcre_split_impl(pcre_cache_entry *pce, zend_string *subject_str,
 	uint32_t		 num_subpats;		/* Number of captured subpatterns */
 	zval			 tmp;
 	pcre2_match_data *match_data;
+	bool old_mdata_used;
 	char *subject = ZSTR_VAL(subject_str);
 
 	no_empty = flags & PREG_SPLIT_NO_EMPTY;
@@ -2595,7 +2604,9 @@ PHPAPI void php_pcre_split_impl(pcre_cache_entry *pce, zend_string *subject_str,
 		goto last;
 	}
 
-	if (!mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+	old_mdata_used = mdata_used;
+	if (!old_mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+		mdata_used = true;
 		match_data = mdata;
 	} else {
 		match_data = pcre2_match_data_create_from_pattern(pce->re, PCRE_G(gctx_zmm));
@@ -2724,6 +2735,7 @@ PHPAPI void php_pcre_split_impl(pcre_cache_entry *pce, zend_string *subject_str,
 	if (match_data != mdata) {
 		pcre2_match_data_free(match_data);
 	}
+	mdata_used = old_mdata_used;
 
 	if (PCRE_G(error_code) != PHP_PCRE_NO_ERROR) {
 		zval_ptr_dtor(return_value);
@@ -2923,6 +2935,7 @@ PHPAPI void  php_pcre_grep_impl(pcre_cache_entry *pce, zval *input, zval *return
 	zend_ulong		 num_key;
 	bool		 invert;			/* Whether to return non-matching
 										   entries */
+	bool old_mdata_used;
 	pcre2_match_data *match_data;
 	invert = flags & PREG_GREP_INVERT ? 1 : 0;
 
@@ -2935,7 +2948,9 @@ PHPAPI void  php_pcre_grep_impl(pcre_cache_entry *pce, zval *input, zval *return
 
 	PCRE_G(error_code) = PHP_PCRE_NO_ERROR;
 
-	if (!mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+	old_mdata_used = mdata_used;
+	if (!old_mdata_used && num_subpats <= PHP_PCRE_PREALLOC_MDATA_SIZE) {
+		mdata_used = true;
 		match_data = mdata;
 	} else {
 		match_data = pcre2_match_data_create_from_pattern(pce->re, PCRE_G(gctx_zmm));
@@ -3001,6 +3016,8 @@ PHPAPI void  php_pcre_grep_impl(pcre_cache_entry *pce, zval *input, zval *return
 		pcre2_match_data_free(match_data);
 	}
 
+	mdata_used = old_mdata_used;
+
 	if (PCRE_G(error_code) != PHP_PCRE_NO_ERROR) {
 		zend_array_destroy(Z_ARR_P(return_value));
 		RETURN_FALSE;
diff --git a/ext/pcre/tests/pcre_reentrancy.phpt b/ext/pcre/tests/pcre_reentrancy.phpt
new file mode 100644
index 0000000000000..5fe4071e4fe17
--- /dev/null
+++ b/ext/pcre/tests/pcre_reentrancy.phpt
@@ -0,0 +1,58 @@
+--TEST--
+PCRE re-entrancy: nested calls should not corrupt global match data
+--EXTENSIONS--
+pcre
+--FILE--
+<?php
+
+echo "Testing nested PCRE calls..." . PHP_EOL;
+
+$subject = 'abc';
+
+// preg_replace_callback is the most common way to trigger re-entrancy
+$result = preg_replace_callback('/./', function($m) {
+    $char = $m[0];
+    echo "Outer match: $char" . PHP_EOL;
+
+    // 1. Nested preg_match
+    preg_match('/./', 'inner', $inner_m);
+
+    // 2. Nested preg_replace (string version)
+    preg_replace('/n/', 'N', 'inner');
+
+    // 3. Nested preg_split
+    preg_split('/n/', 'inner');
+
+    // 4. Nested preg_grep
+    preg_grep('/n/', ['inner']);
+
+    // If any of the above stole the global mdata buffer without setting mdata_used,
+    // the 'offsets' used by this outer preg_replace_callback loop would be corrupted.
+
+    return strtoupper($char);
+}, $subject);
+
+var_dump($result);
+
+echo PHP_EOL . "Testing deep nesting..." . PHP_EOL;
+
+$result = preg_replace_callback('/a/', function($m) {
+    return preg_replace_callback('/b/', function($m) {
+        return preg_replace_callback('/c/', function($m) {
+            return "SUCCESS";
+        }, 'c');
+    }, 'b');
+}, 'a');
+
+var_dump($result);
+
+?>
+--EXPECT--
+Testing nested PCRE calls...
+Outer match: a
+Outer match: b
+Outer match: c
+string(3) "ABC"
+
+Testing deep nesting...
+string(7) "SUCCESS"