diff --git a/src/agents/bash-tools.build-docker-exec-args.test.ts b/src/agents/bash-tools.build-docker-exec-args.test.ts
index b759a51b5..6cdc981f6 100644
--- a/src/agents/bash-tools.build-docker-exec-args.test.ts
+++ b/src/agents/bash-tools.build-docker-exec-args.test.ts
@@ -76,7 +76,7 @@ describe("buildDockerExecArgs", () => {
       tty: false,
     });
 
-    expect(args).toContain("sh");
+    expect(args).toContain("/bin/sh");
     expect(args).toContain("-lc");
   });
 
diff --git a/src/agents/bash-tools.shared.ts b/src/agents/bash-tools.shared.ts
index 2a9bc8216..3cfb92655 100644
--- a/src/agents/bash-tools.shared.ts
+++ b/src/agents/bash-tools.shared.ts
@@ -61,6 +61,12 @@ export function buildDockerExecArgs(params: {
     args.push("-w", params.workdir);
   }
   for (const [key, value] of Object.entries(params.env)) {
+    // Skip PATH — passing a host PATH (e.g. Windows paths) via -e poisons
+    // Docker's executable lookup, causing "sh: not found" on Windows hosts.
+    // PATH is handled separately via OPENCLAW_PREPEND_PATH below.
+    if (key === "PATH") {
+      continue;
+    }
     args.push("-e", `${key}=${value}`);
   }
   const hasCustomPath = typeof params.env.PATH === "string" && params.env.PATH.length > 0;
@@ -75,7 +81,8 @@ export function buildDockerExecArgs(params: {
   const pathExport = hasCustomPath
     ? 'export PATH="${OPENCLAW_PREPEND_PATH}:$PATH"; unset OPENCLAW_PREPEND_PATH; '
     : "";
-  args.push(params.containerName, "sh", "-lc", `${pathExport}${params.command}`);
+  // Use absolute path for sh to avoid dependency on PATH resolution during exec.
+  args.push(params.containerName, "/bin/sh", "-lc", `${pathExport}${params.command}`);
   return args;
 }
 
diff --git a/src/agents/sandbox/docker.ts b/src/agents/sandbox/docker.ts
index df1ba3ef3..e041c2d5c 100644
--- a/src/agents/sandbox/docker.ts
+++ b/src/agents/sandbox/docker.ts
@@ -469,7 +469,7 @@ async function createSandboxContainer(params: {
   await execDocker(["start", name]);
 
   if (cfg.setupCommand?.trim()) {
-    await execDocker(["exec", "-i", name, "sh", "-lc", cfg.setupCommand]);
+    await execDocker(["exec", "-i", name, "/bin/sh", "-lc", cfg.setupCommand]);
   }
 }