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.
History

Thu, 24 Sep 2026 04:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sun, 20 Sep 2026 23:15:00 +0000

Type Values Removed Values Added
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.
Title OpenClaw Canvas Host Route server.ts createCanvasHostHandler denial of service
First Time appeared Openclaw
Openclaw openclaw
Weaknesses CWE-404
CPEs cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:*:*:*
Vendors & Products Openclaw
Openclaw openclaw
References
Metrics cvssV2_0

{'score': 4, 'vector': 'AV:N/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 4.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 4.3, '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'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published: 2026-09-20T23:00:14.987Z

Updated: 2026-09-22T15:41:58.927Z

Reserved: 2026-09-20T09:07:39.802Z

Link: CVE-2026-94094

cve-icon Vulnrichment

Updated: 2026-09-22T15:30:12.623Z

cve-icon NVD

Status : Deferred

Published: 2026-09-20T23:17:03.530

Modified: 2026-09-22T16:18:17.050

Link: CVE-2026-94094

cve-icon Redhat

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