| Component | OpenClaw |
| Severity | medium (CVSS 4.3) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
| Published (NVD) | 2026-09-20 |
| Last modified | 2026-09-22 |
| Affected versions | <= 2026.9.5 read from the advisory text: NVD has not published CPE data yet |
| Fixed in | see the vendor advisory |
| Weakness | CWE-404 |
| CISA KEV | not listed |
NVD 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.
What to do
- NVD lists no fixed version yet: follow the vendor advisory below and keep OpenClaw off the public internet until a fix ships.
- Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-94094
- https://github.com/lche511/cve/tree/main/OpenClaw_Canvas_Big_GET_DoS_Report
- https://vuldb.com/cve/CVE-2026-94094
- https://vuldb.com/submit/882009
- https://vuldb.com/vuln/408023
- https://vuldb.com/vuln/408023/cti
Read more
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