CVE-2026-100555 OpenClaw before 2026.8.1 DNS Rebinding via attachment delivery
An attacker can exploit DNS rebinding in attachment delivery to force the server to fetch private resources, leading to data disclosure.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-100555?
CVE-2026-100555 is a high-severity server-side request forgery vulnerability in OpenClaw, published on 26 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
OpenClaw is an npm-distributed gateway application. In versions >= 2026.7.1 and < 2026.8.1, Synology Chat attachment delivery could lose DNS pinning: the Gateway validated a single DNS result for a supplied file URL but then passed the original hostname to the Synology NAS, where it could resolve to a different destination. When attachment delivery accepted a remotely influenced hostname, an attacker could use DNS rebinding to make the NAS fetch a private or otherwise policy-denied resource and return its contents to the addressed conversation (server-side request forgery). Practical impact depends on NAS routing, resolver behavior, and the response available at the private destination. The issue is fixed in 2026.8.1; as a workaround, disable remote URL attachment forwarding in Synology Chat.
Weakness: CWE-918
Which versions are affected by CVE-2026-100555?
How do I fix CVE-2026-100555?
Upgrade to a fixed version.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-100555 being exploited?
There is no known exploitation of CVE-2026-100555 in the wild and no public exploit code.
Sources
Also known as GHSA-659j-39wf-988v, GHSA-cf95-m4jv-59rc, MINI-74cg-5hq6-fxcr.