diff --git a/NEWS b/NEWS
index ab0204114cb..8d85684e86b 100644
--- a/NEWS
+++ b/NEWS
@@ -36,6 +36,10 @@ PHP                                                                        NEWS
 - Shmop:
   . Fixed bug GH-14537 (shmop Windows 11 crashes the process). (nielsdos)
 
+- SPL:
+  . Fixed bug GH-14639 (Member access within null pointer in
+    ext/spl/spl_observer.c). (nielsdos)
+
 - Standard:
   . Fixed bug GH-14775 (range function overflow with negative step argument).
     (David Carlier)
diff --git a/ext/spl/spl_observer.c b/ext/spl/spl_observer.c
index b996764c1ac..00f25ecbbc4 100644
--- a/ext/spl/spl_observer.c
+++ b/ext/spl/spl_observer.c
@@ -118,9 +118,11 @@ static void spl_object_storage_free_hash(spl_SplObjectStorage *intern, zend_hash
 static void spl_object_storage_dtor(zval *element) /* {{{ */
 {
 	spl_SplObjectStorageElement *el = Z_PTR_P(element);
-	zend_object_release(el->obj);
-	zval_ptr_dtor(&el->inf);
-	efree(el);
+	if (el) {
+		zend_object_release(el->obj);
+		zval_ptr_dtor(&el->inf);
+		efree(el);
+	}
 } /* }}} */
 
 static spl_SplObjectStorageElement* spl_object_storage_get(spl_SplObjectStorage *intern, zend_hash_key *key) /* {{{ */
@@ -168,8 +170,10 @@ static spl_SplObjectStorageElement *spl_object_storage_attach_handle(spl_SplObje
 		return pelement;
 	}
 
+	/* NULL initialization necessary because `spl_object_storage_create_element` could bail out due to OOM. */
+	ZVAL_PTR(entry_zv, NULL);
 	pelement = spl_object_storage_create_element(obj, inf);
-	ZVAL_PTR(entry_zv, pelement);
+	Z_PTR_P(entry_zv) = pelement;
 	return pelement;
 } /* }}} */
 
diff --git a/ext/spl/tests/gh14639.phpt b/ext/spl/tests/gh14639.phpt
new file mode 100644
index 00000000000..1b6f621d27b
--- /dev/null
+++ b/ext/spl/tests/gh14639.phpt
@@ -0,0 +1,21 @@
+--TEST--
+GH-14639 (Member access within null pointer in ext/spl/spl_observer.c)
+--INI--
+memory_limit=2M
+--SKIPIF--
+<?php
+if (getenv("USE_ZEND_ALLOC") === "0") {
+    die("skip Zend MM disabled");
+}
+?>
+--FILE--
+<?php
+$b = new SplObjectStorage();
+for ($i = 10000; $i > 0; $i--) {
+    $object = new StdClass();
+    $object->a = str_repeat("a", 2);
+    $b->attach($object);
+}
+?>
+--EXPECTF--
+Fatal error: Allowed memory size of %d bytes exhausted%s(tried to allocate %d bytes) in %s on line %d