Executive brief
OpenClaw is a media processing library that fetches content from URLs to process media files. When fetching URL-backed media without a proper content-length header, the application buffers the entire response into memory before checking size limits, allowing an attacker to exhaust server memory by sending oversized responses and causing service unavailability.
Technical details
The vulnerability is an uncontrolled resource consumption flaw (CWE-400) in the fetchWithGuard function within src/media/input-files.ts. When content-length is missing or incorrect, the code calls response.arrayBuffer() to read the entire HTTP response body into memory before enforcing maxBytes size checks. An attacker can exploit this by serving a response larger than maxBytes via chunked transfer encoding (which lacks content-length), causing memory exhaustion. The attack requires the vulnerable application to be configured with URL-based media input and for an attacker to control the remote server responding to fetch requests. A patch is available in version 2026.2.14.
Affected products
- OpenClaw openclaw < 2026.2.14
- OpenClaw clawdbot <= 2026.1.24-3
Timeline
- 2026-02-18: disclosed: GHSA-j27p-hq53-9wgc published
- 2026-02-14: patched: Fix commit 00a0890 merged to main; openclaw patched in version 2026.2.14