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).

Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.5%top 59.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

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)

VendorProductVersions
n/a OpenClaw 2026.9.02026.9.12026.9.22026.9.32026.9.42026.9.5

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