diff --git a/docs/bootstrap-inventory.md b/docs/bootstrap-inventory.md
index 2a62ecca6cc9..c7169583eaa7 100644
--- a/docs/bootstrap-inventory.md
+++ b/docs/bootstrap-inventory.md
@@ -27008,7 +27008,7 @@ Rank live CFG gaps across inventory files: `php script/bootstrap-inventory-triag
 ### `ext/standard/Crc32JitHelper.php`
 
 **Warnings** (review for bootstrap subset):
-- 2 class method(s)
+- 7 class method(s)
 
 ### `ext/standard/CslashesJitHelper.php`
 
diff --git a/ext/standard/Crc32JitHelper.php b/ext/standard/Crc32JitHelper.php
index ff3d5c63a02d..553c4c29221d 100644
--- a/ext/standard/Crc32JitHelper.php
+++ b/ext/standard/Crc32JitHelper.php
@@ -5,20 +5,347 @@
 namespace PHPCompiler\ext\standard;
 
 /**
- * crc32()/crc32c() for compiled JIT/AOT modules (#15759, php-in-PHP).
+ * crc32()/crc32c() for compiled JIT/AOT modules (#15759, #27077, php-in-PHP).
  *
- * SSOT: {@see VmCrc32}, {@see VmCrc32c}
+ * NestedJIT-safe CRC32B / CRC32C (peer {@see Bin2hexJitHelper} / {@see StrrevJitHelper}).
+ * Avoid Vm* CRC SSOT call sites and native ord/strlen — NestedJIT stubs those to 0 under thin AOT
+ * (#16075 / #20452 / #15759 helper-bridge wrong-0). Bit-by-bit poly (no lookup table) —
+ * NestedJIT AOT array-table updates miscomputed CRC (#27077).
  * php-src: ext/standard/crc32.c, ext/standard/hash_crc32.c
  */
 final class Crc32JitHelper
 {
+    private const UINT32_MASK = 4294967295;
+
+    /** IEEE CRC32B reflected polynomial (crc32.c). */
+    private const POLY_CRC32B = 3988292384; // 0xEDB88320
+
+    /** Castagnoli CRC32C reflected polynomial (hash_crc32.c). */
+    private const POLY_CRC32C = 2197175160; // 0x82F63B78
+
     public static function crc32Argv(string $data, int $seed): int
     {
-        return VmCrc32::compute($data, $seed);
+        $state = self::u32(((int) $seed) ^ self::UINT32_MASK);
+        $len = self::byteLength($data);
+        for ($i = 0; $i < $len; ++$i) {
+            $state = self::update($state, self::byteOrd($data[$i]), self::POLY_CRC32B);
+        }
+
+        return self::u32(~$state);
     }
 
     public static function crc32cArgv(string $data): int
     {
-        return VmCrc32c::compute($data);
+        $state = self::UINT32_MASK;
+        $len = self::byteLength($data);
+        for ($i = 0; $i < $len; ++$i) {
+            $state = self::update($state, self::byteOrd($data[$i]), self::POLY_CRC32C);
+        }
+
+        return self::u32(~$state);
+    }
+
+    private static function update(int $state, int $byte, int $poly): int
+    {
+        $state = self::u32($state ^ $byte);
+        for ($j = 0; $j < 8; ++$j) {
+            if (($state & 1) !== 0) {
+                $state = self::u32(($state >> 1) ^ $poly);
+            } else {
+                $state = self::u32($state >> 1);
+            }
+        }
+
+        return $state;
+    }
+
+    private static function u32(int $value): int
+    {
+        return $value & self::UINT32_MASK;
+    }
+
+    private static function byteLength(string $data): int
+    {
+        $len = 0;
+        while (isset($data[$len])) {
+            ++$len;
+        }
+
+        return $len;
+    }
+
+    /** NestedJIT-safe byte ordinal (#20452). */
+    private static function byteOrd(string $byte): int
+    {
+        for ($code = 0; $code < 256; ++$code) {
+            if ($byte === self::byteAt($code)) {
+                return $code;
+            }
+        }
+
+        return 0;
+    }
+
+    private static function byteAt(int $code): string
+    {
+        return match ($code) {
+            0 => "\0",
+            1 => "\x01",
+            2 => "\x02",
+            3 => "\x03",
+            4 => "\x04",
+            5 => "\x05",
+            6 => "\x06",
+            7 => "\x07",
+            8 => "\x08",
+            9 => "\x09",
+            10 => "\x0a",
+            11 => "\x0b",
+            12 => "\x0c",
+            13 => "\x0d",
+            14 => "\x0e",
+            15 => "\x0f",
+            16 => "\x10",
+            17 => "\x11",
+            18 => "\x12",
+            19 => "\x13",
+            20 => "\x14",
+            21 => "\x15",
+            22 => "\x16",
+            23 => "\x17",
+            24 => "\x18",
+            25 => "\x19",
+            26 => "\x1a",
+            27 => "\x1b",
+            28 => "\x1c",
+            29 => "\x1d",
+            30 => "\x1e",
+            31 => "\x1f",
+            32 => ' ',
+            33 => '!',
+            34 => '"',
+            35 => '#',
+            36 => '$',
+            37 => '%',
+            38 => '&',
+            39 => "'",
+            40 => '(',
+            41 => ')',
+            42 => '*',
+            43 => '+',
+            44 => ',',
+            45 => '-',
+            46 => '.',
+            47 => '/',
+            48 => '0',
+            49 => '1',
+            50 => '2',
+            51 => '3',
+            52 => '4',
+            53 => '5',
+            54 => '6',
+            55 => '7',
+            56 => '8',
+            57 => '9',
+            58 => ':',
+            59 => ';',
+            60 => '<',
+            61 => '=',
+            62 => '>',
+            63 => '?',
+            64 => '@',
+            65 => 'A',
+            66 => 'B',
+            67 => 'C',
+            68 => 'D',
+            69 => 'E',
+            70 => 'F',
+            71 => 'G',
+            72 => 'H',
+            73 => 'I',
+            74 => 'J',
+            75 => 'K',
+            76 => 'L',
+            77 => 'M',
+            78 => 'N',
+            79 => 'O',
+            80 => 'P',
+            81 => 'Q',
+            82 => 'R',
+            83 => 'S',
+            84 => 'T',
+            85 => 'U',
+            86 => 'V',
+            87 => 'W',
+            88 => 'X',
+            89 => 'Y',
+            90 => 'Z',
+            91 => '[',
+            92 => '\\',
+            93 => ']',
+            94 => '^',
+            95 => '_',
+            96 => '`',
+            97 => 'a',
+            98 => 'b',
+            99 => 'c',
+            100 => 'd',
+            101 => 'e',
+            102 => 'f',
+            103 => 'g',
+            104 => 'h',
+            105 => 'i',
+            106 => 'j',
+            107 => 'k',
+            108 => 'l',
+            109 => 'm',
+            110 => 'n',
+            111 => 'o',
+            112 => 'p',
+            113 => 'q',
+            114 => 'r',
+            115 => 's',
+            116 => 't',
+            117 => 'u',
+            118 => 'v',
+            119 => 'w',
+            120 => 'x',
+            121 => 'y',
+            122 => 'z',
+            123 => '{',
+            124 => '|',
+            125 => '}',
+            126 => '~',
+            127 => "\x7f",
+            128 => "\x80",
+            129 => "\x81",
+            130 => "\x82",
+            131 => "\x83",
+            132 => "\x84",
+            133 => "\x85",
+            134 => "\x86",
+            135 => "\x87",
+            136 => "\x88",
+            137 => "\x89",
+            138 => "\x8a",
+            139 => "\x8b",
+            140 => "\x8c",
+            141 => "\x8d",
+            142 => "\x8e",
+            143 => "\x8f",
+            144 => "\x90",
+            145 => "\x91",
+            146 => "\x92",
+            147 => "\x93",
+            148 => "\x94",
+            149 => "\x95",
+            150 => "\x96",
+            151 => "\x97",
+            152 => "\x98",
+            153 => "\x99",
+            154 => "\x9a",
+            155 => "\x9b",
+            156 => "\x9c",
+            157 => "\x9d",
+            158 => "\x9e",
+            159 => "\x9f",
+            160 => "\xa0",
+            161 => "\xa1",
+            162 => "\xa2",
+            163 => "\xa3",
+            164 => "\xa4",
+            165 => "\xa5",
+            166 => "\xa6",
+            167 => "\xa7",
+            168 => "\xa8",
+            169 => "\xa9",
+            170 => "\xaa",
+            171 => "\xab",
+            172 => "\xac",
+            173 => "\xad",
+            174 => "\xae",
+            175 => "\xaf",
+            176 => "\xb0",
+            177 => "\xb1",
+            178 => "\xb2",
+            179 => "\xb3",
+            180 => "\xb4",
+            181 => "\xb5",
+            182 => "\xb6",
+            183 => "\xb7",
+            184 => "\xb8",
+            185 => "\xb9",
+            186 => "\xba",
+            187 => "\xbb",
+            188 => "\xbc",
+            189 => "\xbd",
+            190 => "\xbe",
+            191 => "\xbf",
+            192 => "\xc0",
+            193 => "\xc1",
+            194 => "\xc2",
+            195 => "\xc3",
+            196 => "\xc4",
+            197 => "\xc5",
+            198 => "\xc6",
+            199 => "\xc7",
+            200 => "\xc8",
+            201 => "\xc9",
+            202 => "\xca",
+            203 => "\xcb",
+            204 => "\xcc",
+            205 => "\xcd",
+            206 => "\xce",
+            207 => "\xcf",
+            208 => "\xd0",
+            209 => "\xd1",
+            210 => "\xd2",
+            211 => "\xd3",
+            212 => "\xd4",
+            213 => "\xd5",
+            214 => "\xd6",
+            215 => "\xd7",
+            216 => "\xd8",
+            217 => "\xd9",
+            218 => "\xda",
+            219 => "\xdb",
+            220 => "\xdc",
+            221 => "\xdd",
+            222 => "\xde",
+            223 => "\xdf",
+            224 => "\xe0",
+            225 => "\xe1",
+            226 => "\xe2",
+            227 => "\xe3",
+            228 => "\xe4",
+            229 => "\xe5",
+            230 => "\xe6",
+            231 => "\xe7",
+            232 => "\xe8",
+            233 => "\xe9",
+            234 => "\xea",
+            235 => "\xeb",
+            236 => "\xec",
+            237 => "\xed",
+            238 => "\xee",
+            239 => "\xef",
+            240 => "\xf0",
+            241 => "\xf1",
+            242 => "\xf2",
+            243 => "\xf3",
+            244 => "\xf4",
+            245 => "\xf5",
+            246 => "\xf6",
+            247 => "\xf7",
+            248 => "\xf8",
+            249 => "\xf9",
+            250 => "\xfa",
+            251 => "\xfb",
+            252 => "\xfc",
+            253 => "\xfd",
+            254 => "\xfe",
+            255 => "\xff",
+            default => "\0",
+        };
     }
 }
diff --git a/lib/JIT/Builtin/Crc32Runtime.php b/lib/JIT/Builtin/Crc32Runtime.php
index 93449114a758..1122a60537fe 100644
--- a/lib/JIT/Builtin/Crc32Runtime.php
+++ b/lib/JIT/Builtin/Crc32Runtime.php
@@ -9,10 +9,12 @@
 use PHPLLVM\Value;
 
 /**
- * JIT/AOT link for crc32()/crc32c() via Crc32JitHelper PHP (#15759).
+ * JIT/AOT link for crc32()/crc32c() via NestedJIT-safe Crc32JitHelper PHP (#15759, #27077).
  *
  * Replaces inline CRC table LLVM in ext/standard/JitCrcCore.php.
- * SSOT: {@see \PHPCompiler\ext\standard\VmCrc32}, {@see \PHPCompiler\ext\standard\VmCrc32c}.
+ * Helper compile: {@see JitVmHelperLink::ensureBridge} (MathSqrt #27888 / Bin2hex #20452 shape).
+ * SSOT parity: {@see \PHPCompiler\ext\standard\VmCrc32}, {@see \PHPCompiler\ext\standard\VmCrc32c}
+ * (algorithms inlined into the helper — NestedJIT must not call Vm* under thin AOT).
  */
 final class Crc32Runtime
 {
@@ -32,6 +34,10 @@ final class Crc32Runtime
         self::CRC32C_HELPER,
     ];
 
+    private const CRC32_BRIDGE_ENTRY = 'crc32_bridge_entry';
+
+    private const CRC32C_BRIDGE_ENTRY = 'crc32c_bridge_entry';
+
     public static function ensureLinked(Context $context): void
     {
         self::implementCrc32($context);
@@ -61,35 +67,49 @@ public static function invokeCrc32c(Context $context, Value $subject): Value
 
     private static function implementCrc32(Context $context): void
     {
+        $probe = $context->module->getNamedFunction(self::ABI_CRC32);
+        if (JitVmHelperLink::hasNamedBridgeEntry($probe, self::CRC32_BRIDGE_ENTRY)) {
+            $context->registerFunction(self::ABI_CRC32, $probe);
+
+            return;
+        }
+
         $strPtr = $context->getTypeFromString('__string__*');
         $i64 = $context->getTypeFromString('int64');
         JitVmHelperLink::ensureBridge(
             $context,
             self::ABI_CRC32,
-            'crc32_bridge_entry',
+            self::CRC32_BRIDGE_ENTRY,
             [$strPtr, $i64],
             $i64,
             self::CRC32_HELPER,
             self::HELPER_PATH,
             self::COMPILED_HELPERS,
-            '#15759'
+            '#27077'
         );
     }
 
     private static function implementCrc32c(Context $context): void
     {
+        $probe = $context->module->getNamedFunction(self::ABI_CRC32C);
+        if (JitVmHelperLink::hasNamedBridgeEntry($probe, self::CRC32C_BRIDGE_ENTRY)) {
+            $context->registerFunction(self::ABI_CRC32C, $probe);
+
+            return;
+        }
+
         $strPtr = $context->getTypeFromString('__string__*');
         $i64 = $context->getTypeFromString('int64');
         JitVmHelperLink::ensureBridge(
             $context,
             self::ABI_CRC32C,
-            'crc32c_bridge_entry',
+            self::CRC32C_BRIDGE_ENTRY,
             [$strPtr],
             $i64,
             self::CRC32C_HELPER,
             self::HELPER_PATH,
             self::COMPILED_HELPERS,
-            '#15759'
+            '#27077'
         );
     }
 }
diff --git a/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/manifest.json b/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/manifest.json
index ef12ba1cff59..51fb2ca9de04 100644
--- a/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/manifest.json
+++ b/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/manifest.json
@@ -1 +1 @@
-{"fingerprint":"76aa5caaedadabc300e5","fingerprint_version":2,"unit":"/ext/standard/Crc32JitHelper.php","deps":["/ext/standard/Crc32JitHelper.php","/ext/standard/VmCrc32.php","/ext/standard/VmCrc32c.php"],"helpers":{"phpcompiler\\ext\\standard\\crc32jithelper::crc32argv":"PHPCompiler_ext_standard_Crc32JitHelper__crc32argv","phpcompiler\\ext\\standard\\crc32jithelper::crc32cargv":"PHPCompiler_ext_standard_Crc32JitHelper__crc32cargv"},"init_symbol":"__init__unit_ext_standard_Crc32JitHelper_php","shutdown_symbol":"__shutdown__unit_ext_standard_Crc32JitHelper_php","init_via_global_ctor":true,"runtime_safe":true}
+{"fingerprint":"13668bf24759d27adf22","fingerprint_version":2,"unit":"/ext/standard/Crc32JitHelper.php","deps":["/ext/standard/Crc32JitHelper.php"],"helpers":{"phpcompiler\\ext\\standard\\crc32jithelper::crc32argv":"PHPCompiler_ext_standard_Crc32JitHelper__crc32argv","phpcompiler\\ext\\standard\\crc32jithelper::crc32cargv":"PHPCompiler_ext_standard_Crc32JitHelper__crc32cargv"},"init_symbol":"__init__unit_ext_standard_Crc32JitHelper_php","shutdown_symbol":"__shutdown__unit_ext_standard_Crc32JitHelper_php","init_via_global_ctor":true,"runtime_safe":true}
diff --git a/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/unit.o b/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/unit.o
index a1edd490591b..66e2fbecf0b6 100644
Binary files a/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/unit.o and b/prelinked/helper-runtime/x86_64-linux/units/ext_standard_Crc32JitHelper_php/unit.o differ
diff --git a/test/aot/AotTest.php b/test/aot/AotTest.php
index 55fb6021b4a9..430255d1fd9d 100644
--- a/test/aot/AotTest.php
+++ b/test/aot/AotTest.php
@@ -247,10 +247,6 @@ public static function providePHPTests(): \Generator
             if (!CompilerVersion::supportsCrc32c() && str_contains($name, 'crc32c')) {
                 continue;
             }
-            // crc32c AOT native execute via helper bridge returns 0 (#15759); VM+JIT compliance covers parity.
-            if (CompilerVersion::supportsCrc32c() && str_contains($name, 'crc32c')) {
-                continue;
-            }
             // AOT mb_str_pad_*_forward* / json_validate_*_forward* fixtures set PROFILE via --ENV--; always include (#22373, #22544).
             if (!CompilerVersion::supportsMbStrPad()
                 && str_contains($name, 'mb_str_pad')
diff --git a/test/repro/issue_27077_crc32_aot.php b/test/repro/issue_27077_crc32_aot.php
new file mode 100644
index 000000000000..ba23efab603a
--- /dev/null
+++ b/test/repro/issue_27077_crc32_aot.php
@@ -0,0 +1,3 @@
+<?php
+// AOT crc32() must match Zend (#27077 — NestedJIT-safe Crc32JitHelper, not VmCrc32 stub→0).
+echo crc32('php-compiler'), PHP_EOL;
diff --git a/test/unit/Crc32RuntimeShrinkTest.php b/test/unit/Crc32RuntimeShrinkTest.php
index d409c33269f5..5b51bd8239bf 100644
--- a/test/unit/Crc32RuntimeShrinkTest.php
+++ b/test/unit/Crc32RuntimeShrinkTest.php
@@ -9,7 +9,7 @@
 use PHPCompiler\ext\standard\VmCrc32c;
 use PHPUnit\Framework\TestCase;
 
-/** crc32()/crc32c() JIT routes through Crc32JitHelper PHP not JitCrcCore LLVM (#15759). */
+/** crc32()/crc32c() JIT routes through NestedJIT-safe Crc32JitHelper PHP (#15759, #27077). */
 final class Crc32RuntimeShrinkTest extends TestCase
 {
     public function testJitCrc32DelegatesToRuntimeBridge(): void
@@ -31,9 +31,23 @@ public function testCrc32CoreFileRemoved(): void
         $this->assertFileDoesNotExist(__DIR__.'/../../ext/standard/JitCrcCore.php');
     }
 
+    public function testCrc32JitHelperIsNestedJitSelfContained(): void
+    {
+        $source = (string) file_get_contents(__DIR__.'/../../ext/standard/Crc32JitHelper.php');
+        // Call sites only — docblock may name the VM SSOT / banned builtins for humans.
+        $this->assertStringNotContainsString('VmCrc32::', $source);
+        $this->assertStringNotContainsString('VmCrc32c::', $source);
+        $this->assertStringNotContainsString('VmString::', $source);
+        $this->assertStringNotContainsString('\\ord(', $source);
+        $this->assertStringNotContainsString('\\strlen(', $source);
+    }
+
     public function testCrc32JitHelperMatchesVmSsot(): void
     {
         $this->assertSame(VmCrc32::compute('abc', 0), Crc32JitHelper::crc32Argv('abc', 0));
         $this->assertSame(VmCrc32c::compute('abc'), Crc32JitHelper::crc32cArgv('abc'));
+        $this->assertSame(4282364586, Crc32JitHelper::crc32Argv('php-compiler', 0));
+        $seed = VmCrc32::compute('f', 0);
+        $this->assertSame(VmCrc32::compute('oo', $seed), Crc32JitHelper::crc32Argv('oo', $seed));
     }
 }
diff --git a/test/unit/Crc32cBuiltinTest.php b/test/unit/Crc32cBuiltinTest.php
index 303ee1d8a178..f65ea43ea5c4 100644
--- a/test/unit/Crc32cBuiltinTest.php
+++ b/test/unit/Crc32cBuiltinTest.php
@@ -39,7 +39,6 @@ public function testVmMatchesPhpSubset(): void
      */
     public function testAotNativeBinaryMatchesPhpSubset(): void
     {
-        $this->markTestSkipped('crc32/crc32c AOT native execute via helper bridge returns 0 (#15759); VM+JIT compliance green');
         if (!LlvmToolchain::isReady(dirname(__DIR__, 2))) {
             $this->markTestSkipped('LLVM 9 toolchain not available');
         }