CVE-2026-100555: OpenClaw before 2026.8.1 DNS Rebinding via attachment delivery
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
OpenClawto a version that resolves this vulnerability.Fixed in 2026.8.1 - Configuration
Disable remote URL attachment forwarding in Synology Chat as a workaround.
Synology Chat remote URL attachment forwarding = disabled
Event History
Frequently Asked Questions
Which deployments are exposed?
OpenClaw versions 2026.7.1 through versions before 2026.8.1 are affected when Synology Chat attachment delivery accepts a remotely influenced hostname. Practical exposure also depends on the NAS network routes, DNS resolver behavior, and whether a reachable private or policy-denied service returns useful content.
What does an attacker need to exploit this issue?
An attacker needs to supply a file URL through the affected attachment-delivery path with a hostname they can influence for DNS rebinding. They also need the Synology NAS to resolve that hostname differently after the Gateway's initial validation, toward a resource the NAS can access.
What can be done if upgrading is not immediately possible?
Disable remote URL attachment forwarding in Synology Chat. This prevents the affected attachment-delivery behavior from fetching attacker-supplied remote URLs.
What is the potential impact of successful exploitation?
The NAS may fetch a private or otherwise policy-denied resource and return its contents to the addressed conversation. This can expose content available to the NAS, with impact determined by the reachable destination and its response.