OpenClaw Canvas Host Route server.ts createCanvasHostHandler denial of service
33Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 5.3epss 0.3%
exploitation probability
0.3%top 80% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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.
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
Affected products
n/a · OpenClawpublic PoCs found — 1
cve_referencegithub.com/lche511/cve/tree/main/OpenClaw_Canvas_Big_GET_DoS_Reportunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.