diff --git a/NEWS b/NEWS
index a09aafc0b84..966fbf97a1c 100644
--- a/NEWS
+++ b/NEWS
@@ -49,6 +49,9 @@ PHP                                                                        NEWS
   . Added get_error_handler(), get_exception_handler() functions. (Arnaud)
   . Fixed bug GH-15753 and GH-16198 (Bind traits before parent class). (ilutov)
   . Added support for casts in constant expressions. (nielsdos)
+  . Fixed bugs GH-17711 and GH-18022 (Infinite recursion on deprecated attribute
+    evaluation) and GH-18464 (Recursion protection for deprecation constants not
+    released on bailout). (DanielEScherzer and ilutov)
 
 - Curl:
   . Added curl_multi_get_handles(). (timwolla)
diff --git a/Zend/tests/constants/gh18463-class-constant.phpt b/Zend/tests/constants/gh18463-class-constant.phpt
new file mode 100644
index 00000000000..2af977205dc
--- /dev/null
+++ b/Zend/tests/constants/gh18463-class-constant.phpt
@@ -0,0 +1,20 @@
+--TEST--
+GH-18463: Recursion protection should not be applied to internal class constants
+--EXTENSIONS--
+zend_test
+--FILE--
+<?php
+
+function handler($errno, $errstr, $errfile, $errline) {
+	echo "$errstr in $errfile on line $errline\n";
+	eval('class string {}');
+}
+
+set_error_handler('handler');
+
+var_dump(_ZendTestClass::ZEND_TEST_DEPRECATED);
+?>
+--EXPECTF--
+Constant _ZendTestClass::ZEND_TEST_DEPRECATED is deprecated in %s on line %d
+
+Fatal error: Cannot use "string" as a class name as it is reserved in %s(%d) : eval()'d code on line %d
diff --git a/Zend/zend_constants.c b/Zend/zend_constants.c
index 28a4b7b048c..1e6ad5a69dd 100644
--- a/Zend/zend_constants.c
+++ b/Zend/zend_constants.c
@@ -373,9 +373,15 @@ ZEND_API zval *zend_get_class_constant_ex(zend_string *class_name, zend_string *
 
 			if (UNEXPECTED(ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED)) {
 				if ((flags & ZEND_FETCH_CLASS_SILENT) == 0 && !CONST_IS_RECURSIVE(c)) {
+					if (c->ce->type == ZEND_USER_CLASS) {
+						/* Recursion protection only applied to user constants, GH-18463 */
+						CONST_PROTECT_RECURSION(c);
+					}
 					CONST_PROTECT_RECURSION(c);
 					zend_deprecated_class_constant(c, constant_name);
-					CONST_UNPROTECT_RECURSION(c);
+					if (c->ce->type == ZEND_USER_CLASS) {
+						CONST_UNPROTECT_RECURSION(c);
+					}
 					if (EG(exception)) {
 						goto failure;
 					}
diff --git a/Zend/zend_vm_def.h b/Zend/zend_vm_def.h
index ef279f5395d..95d9a44f80d 100644
--- a/Zend/zend_vm_def.h
+++ b/Zend/zend_vm_def.h
@@ -6156,10 +6156,15 @@ ZEND_VM_HANDLER(181, ZEND_FETCH_CLASS_CONSTANT, VAR|CONST|UNUSED|CLASS_FETCH, CO
 			}
 
 			bool is_constant_deprecated = ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED;
-			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {
-				CONST_PROTECT_RECURSION(c);
+			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {			
+				if (c->ce->type == ZEND_USER_CLASS) {
+					/* Recursion protection only applied to user constants, GH-18463 */
+					CONST_PROTECT_RECURSION(c);
+				}
 				zend_deprecated_class_constant(c, constant_name);
-				CONST_UNPROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					CONST_UNPROTECT_RECURSION(c);
+				}
 
 				if (EG(exception)) {
 					ZVAL_UNDEF(EX_VAR(opline->result.var));
diff --git a/Zend/zend_vm_execute.h b/Zend/zend_vm_execute.h
index d55cad75d02..aa1c8e7e175 100644
--- a/Zend/zend_vm_execute.h
+++ b/Zend/zend_vm_execute.h
@@ -7669,9 +7669,14 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_CONS
 
 			bool is_constant_deprecated = ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED;
 			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {
-				CONST_PROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					/* Recursion protection only applied to user constants, GH-18463 */
+					CONST_PROTECT_RECURSION(c);
+				}
 				zend_deprecated_class_constant(c, constant_name);
-				CONST_UNPROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					CONST_UNPROTECT_RECURSION(c);
+				}
 
 				if (EG(exception)) {
 					ZVAL_UNDEF(EX_VAR(opline->result.var));
@@ -8874,9 +8879,14 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_CONS
 
 			bool is_constant_deprecated = ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED;
 			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {
-				CONST_PROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					/* Recursion protection only applied to user constants, GH-18463 */
+					CONST_PROTECT_RECURSION(c);
+				}
 				zend_deprecated_class_constant(c, constant_name);
-				CONST_UNPROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					CONST_UNPROTECT_RECURSION(c);
+				}
 
 				if (EG(exception)) {
 					ZVAL_UNDEF(EX_VAR(opline->result.var));
@@ -25970,9 +25980,14 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_VAR_
 
 			bool is_constant_deprecated = ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED;
 			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {
-				CONST_PROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					/* Recursion protection only applied to user constants, GH-18463 */
+					CONST_PROTECT_RECURSION(c);
+				}
 				zend_deprecated_class_constant(c, constant_name);
-				CONST_UNPROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					CONST_UNPROTECT_RECURSION(c);
+				}
 
 				if (EG(exception)) {
 					ZVAL_UNDEF(EX_VAR(opline->result.var));
@@ -26542,9 +26557,14 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_VAR_
 
 			bool is_constant_deprecated = ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED;
 			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {
-				CONST_PROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					/* Recursion protection only applied to user constants, GH-18463 */
+					CONST_PROTECT_RECURSION(c);
+				}
 				zend_deprecated_class_constant(c, constant_name);
-				CONST_UNPROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					CONST_UNPROTECT_RECURSION(c);
+				}
 
 				if (EG(exception)) {
 					ZVAL_UNDEF(EX_VAR(opline->result.var));
@@ -35385,9 +35405,14 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_UNUS
 
 			bool is_constant_deprecated = ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED;
 			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {
-				CONST_PROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					/* Recursion protection only applied to user constants, GH-18463 */
+					CONST_PROTECT_RECURSION(c);
+				}
 				zend_deprecated_class_constant(c, constant_name);
-				CONST_UNPROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					CONST_UNPROTECT_RECURSION(c);
+				}
 
 				if (EG(exception)) {
 					ZVAL_UNDEF(EX_VAR(opline->result.var));
@@ -35747,9 +35772,14 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_FETCH_CLASS_CONSTANT_SPEC_UNUS
 
 			bool is_constant_deprecated = ZEND_CLASS_CONST_FLAGS(c) & ZEND_ACC_DEPRECATED;
 			if (UNEXPECTED(is_constant_deprecated) && !CONST_IS_RECURSIVE(c)) {
-				CONST_PROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					/* Recursion protection only applied to user constants, GH-18463 */
+					CONST_PROTECT_RECURSION(c);
+				}
 				zend_deprecated_class_constant(c, constant_name);
-				CONST_UNPROTECT_RECURSION(c);
+				if (c->ce->type == ZEND_USER_CLASS) {
+					CONST_UNPROTECT_RECURSION(c);
+				}
 
 				if (EG(exception)) {
 					ZVAL_UNDEF(EX_VAR(opline->result.var));