diff --git a/Cargo.lock b/Cargo.lock
index c3f7de35..e59f89b9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1160,7 +1160,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_builtins"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "chrono",
  "fast-float",
@@ -1185,7 +1185,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_bytecode"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "num-bigint",
  "oxide_log",
@@ -1193,7 +1193,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cfg"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_emit",
@@ -1204,7 +1204,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cli"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "ansi_term",
  "bumpalo",
@@ -1226,7 +1226,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_code_cache"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "lru",
  "oxide_bytecode",
@@ -1235,7 +1235,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_compiler"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1255,7 +1255,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_dce"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1269,7 +1269,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_emit"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "num-bigint",
  "oxc_allocator",
@@ -1284,7 +1284,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_engine"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1296,7 +1296,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_ir"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_log",
@@ -1305,7 +1305,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_kernel"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1319,7 +1319,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_liveness"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1331,7 +1331,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_log"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "tracing",
  "tracing-appender",
@@ -1340,7 +1340,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_parser"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxc_allocator",
  "oxc_ast",
@@ -1355,7 +1355,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_regalloc"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1371,7 +1371,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_runtime_api"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "num-bigint",
  "num-traits",
@@ -1384,7 +1384,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_test262"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1402,7 +1402,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_types"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1415,7 +1415,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_vm"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "bumpalo",
  "chrono",
diff --git a/Cargo.toml b/Cargo.toml
index d88e7740..452a8f48 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.14.2"
+version = "0.14.3"
 edition = "2021"
 license = "MIT"
 rust-version = "1.80"
diff --git a/crates/oxide_test262/src/config.rs b/crates/oxide_test262/src/config.rs
index 3eda7b19..6d4e5f30 100644
--- a/crates/oxide_test262/src/config.rs
+++ b/crates/oxide_test262/src/config.rs
@@ -95,7 +95,7 @@ impl RunConfig {
           \x20  OXIDE_TEST262_CHUNK_SIZE             tests per child in chunked mode\n\
           \x20  OXIDE_TEST262_CHILD_CHUNK            marks a spawned child as chunk worker (any value)\n\
           \x20  OXIDE_TEST262_ALLOW_FAIL_EXIT        child may exit 1 on fail (any value)\n\
-          \x20  OXIDE_TEST262_KERNEL_BATCH           kernel rebuilds every N tests (default 256, kept under the 512 realm bound)\n\
+          \x20  OXIDE_TEST262_KERNEL_BATCH           kernel rebuilds every N tests (default 256, clamped to the 512 realm bound)\n\
           \x20  OXIDE_TEST262_LOG_LEVEL              runner log level (default info)\n\
           \x20  OXIDE_SKIP_UNTIL                      skip test indexes below N (chunking/supervise resume)\n\
           \x20  OXIDE_MAX_TESTS                       run at most N tests after skip point"
diff --git a/crates/oxide_test262/src/main.rs b/crates/oxide_test262/src/main.rs
index 5aec3c27..cfa9b7a5 100644
--- a/crates/oxide_test262/src/main.rs
+++ b/crates/oxide_test262/src/main.rs
@@ -29,6 +29,10 @@ use runner::{build_runner_engine, process_path, CURRENT_TEST_PATH};
 use stats::RunStats;
 use supervise::run_supervised;
 
+/// kernel 重建批次的上界：realm 编号受属性键符号空间约束须小于 512，
+/// 单个 kernel 生命周期至多创建 512 个 Vm；用户配置超此值时钳到该上界。
+const MAX_KERNEL_BATCH: usize = 512;
+
 /// 程序入口：安装带当前测试路径的 panic hook，并在大栈线程上运行测试。
 fn main() {
     // 安装 panic hook，打印崩溃发生时正在运行的测试。
@@ -174,11 +178,13 @@ fn run_tests() -> bool {
         .map(|n| n.min(total))
         .unwrap_or(total);
     // 缺省 256：每 kernel 生命周期 realm 计数不超 512 上界（属性键符号空间约束），
-    // 留一倍余量防重建边界 off-by-one 触发 debug 断言。
+    // 留一倍余量防重建边界 off-by-one 触发 debug 断言；用户配置超上界时钳到
+    // MAX_KERNEL_BATCH（断言要求编号 < 512，即每 kernel 生命周期至多 512 个 Vm）。
     let kernel_batch = std::env::var("OXIDE_TEST262_KERNEL_BATCH")
         .ok()
         .and_then(|s| s.parse::<usize>().ok())
         .filter(|&n| n > 0)
+        .map(|n| n.min(MAX_KERNEL_BATCH))
         .unwrap_or(256);
     let chunk_size = std::env::var("OXIDE_TEST262_CHUNK_SIZE")
         .ok()