Vulnerability · Published Sep 20, 2026 · Assigned by VulDB
CVE-2026-94094OpenClaw Canvas Host Route server.ts createCanvasHostHandler denial of service
Medium 4.3
In plain English
A medium-severity security flaw in OpenClaw. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities).
Official description
A flaw has been found in OpenClaw up to 2026.9.5. Affected is the function createCanvasHostHandler of the file extensions/canvas/src/host/server.ts of the component Canvas Host Route. Executing a manipulation can lead to denial of service. The attack can be launched remotely. The exploit has been published and may be used. Fix suggestion's "streaming/size-limit" was never shipped - latest 2026.9.5 still buffers the whole file via readFile() (src/canvas/serve.runtime.ts:17,114), unlike the sibling WS path which caps at 64KB. The vendor was contacted early about this disclosure.
Affected products (as reported)
Weakness: CWE-404 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
References
- VDB-408023 | OpenClaw Canvas Host Route server.ts createCanvasHostHandler denial of service vdb-entry, technical-description
- VDB-408023 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
- CVE-2026-94094 | CVE Analysis and Report third-party-advisory
- Submit #882009 | OpenClaw openclaw@2026.6.11 Denial of Service third-party-advisory
- https://github.com/lche511/cve/tree/main/OpenClaw_Canvas_Big_GET_DoS_Report exploit