diff --git a/src/plugins/bundled-runtime-deps.test.ts b/src/plugins/bundled-runtime-deps.test.ts
index 70aecfced78..70b9d911eef 100644
--- a/src/plugins/bundled-runtime-deps.test.ts
+++ b/src/plugins/bundled-runtime-deps.test.ts
@@ -1696,6 +1696,42 @@ describe("ensureBundledPluginRuntimeDeps", () => {
     ).toEqual({ installedSpecs: [], retainSpecs: [] });
   });
 
+  it("resolves nested cache pluginRoot to enclosing versioned cache (regression for #72956)", () => {
+    const packageRoot = makeTempDir();
+    const stageDir = makeTempDir();
+    fs.writeFileSync(
+      path.join(packageRoot, "package.json"),
+      JSON.stringify({ name: "openclaw", version: "2026.4.25" }),
+    );
+    const pluginRoot = path.join(packageRoot, "dist", "extensions", "telegram");
+    fs.mkdirSync(pluginRoot, { recursive: true });
+    fs.writeFileSync(
+      path.join(pluginRoot, "package.json"),
+      JSON.stringify({ dependencies: { grammy: "^1.42.0" } }),
+    );
+    const env = { OPENCLAW_PLUGIN_STAGE_DIR: stageDir };
+    const installRoot = resolveBundledRuntimeDependencyInstallRoot(pluginRoot, { env });
+
+    // Simulate a deeply-nested pluginRoot inside the existing cache directory
+    // (e.g. plugin-sdk loaded as a transitive dep). The path no longer matches
+    // `<root>/dist/extensions/<plugin>`, so resolveBundledPluginPackageRoot()
+    // returns null and the caller previously fell back to the raw pluginRoot,
+    // generating a self-referential `openclaw-unknown-*` cache directory.
+    const nestedPluginRoot = path.join(
+      installRoot,
+      "dist",
+      "extensions",
+      "node_modules",
+      "openclaw",
+      "plugin-sdk",
+    );
+    fs.mkdirSync(nestedPluginRoot, { recursive: true });
+
+    const resolved = resolveBundledRuntimeDependencyInstallRoot(nestedPluginRoot, { env });
+    expect(resolved).toBe(installRoot);
+    expect(path.basename(resolved).startsWith("openclaw-unknown-")).toBe(false);
+  });
+
   it("links source-checkout runtime deps from the cache instead of copying them", () => {
     const packageRoot = makeTempDir();
     fs.writeFileSync(
diff --git a/src/plugins/bundled-runtime-deps.ts b/src/plugins/bundled-runtime-deps.ts
index 42d301186de..324eb3eae1e 100644
--- a/src/plugins/bundled-runtime-deps.ts
+++ b/src/plugins/bundled-runtime-deps.ts
@@ -977,18 +977,20 @@ function resolveExistingExternalBundledRuntimeDepsRoots(params: {
   const externalBaseDirs = resolveBundledRuntimeDepsExternalBaseDirs(params.env);
   for (const externalBaseDir of externalBaseDirs) {
     const relative = path.relative(path.resolve(externalBaseDir), packageRoot);
-    if (
-      relative === "" ||
-      relative.startsWith("..") ||
-      path.isAbsolute(relative) ||
-      relative.includes(path.sep)
-    ) {
+    if (relative === "" || relative.startsWith("..") || path.isAbsolute(relative)) {
       continue;
     }
-    const packageKey = path.basename(packageRoot);
-    return packageKey.startsWith("openclaw-")
-      ? externalBaseDirs.map((baseDir) => path.join(baseDir, packageKey))
-      : null;
+    // Accept both `<base>/<key>` and any descendant such as
+    // `<base>/<key>/dist/extensions/node_modules/openclaw/plugin-sdk`.
+    // Without this, when a bundled package re-enters resolution via a nested
+    // `pluginRoot` (e.g. plugin-sdk loaded as a dependency), the caller falls
+    // back to `params.pluginRoot`, which lacks a `package.json`, producing a
+    // self-referential `openclaw-unknown-*` cache directory (#72956).
+    const packageKey = relative.split(path.sep)[0];
+    if (!packageKey || !packageKey.startsWith("openclaw-")) {
+      continue;
+    }
+    return externalBaseDirs.map((baseDir) => path.join(baseDir, packageKey));
   }
   return null;
 }