Affected: OpenClaw

OpenClaw versions prior to 2026.2.14 contain a denial of service vulnerability in the fetchWithGuard function that allocates entire response payloads in memory before enforcing maxBytes limits. Remote attackers can trigger memory exhaustion by serving oversized responses without content-length headers to cause availability loss.

Affected: npm: openclaw

### Summary URL-backed media fetch handling allocated the entire response payload in memory (`arrayBuffer`) before enforcing `maxBytes`, allowing oversized responses to cause memory exhaustion.

### Affected Versions - `openclaw` (npm): < `2026.2.14` - `clawdbot` (npm): <= `2026.1.24-3`

### Patched Versions - `openclaw` (npm): `2026.2.14`

### Fix Commit - `openclaw/openclaw` `main`: `00a08908892d1743d1fc52e5cbd9499dd5da2fe0`

### Details Affected component: - `src/media/input-files.ts` (`fetchWithGuard`)

When `content-length` is missing or incorrect, reading the body via `response.arrayBuffer()` buffers the full payload before a size check can run.

### Proof of Concept 1. Configure URL-based media input. 2. Serve a response larger than `maxBytes` (chunked transfer / no `content-length`). 3. Trigger the `fetchWithGuard` URL fetch path.

Example local server (large response): ```bash node -e 'require("http").createServer((_,res)=>{res.writeHead(200,{"content-type":"application/octet-stream"});for(let i=0;i<1024;i++)res.write(Buffer.alloc(1024*64));res.end();}).listen(18888)' ```

### Impact Availability loss via memory pressure from attacker-controlled remote media responses.

### Mitigation Until a patched release is available, disable URL-backed media inputs (or restrict to a tight hostname allowlist) and use conservative `maxBytes` limits.

### Credits Reported by @vincentkoc.