CVE-2026-100555

HIGH
Published Sep 26, 2026 Modified Sep 28, 2026 CWE-918

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.

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CVSS v3.1 Score

7.1
HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N

EPSS — Exploit Prediction

0.0020
Probability of exploitation
0.09%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-918 Server-Side Request Forgery (SSRF)

References

Frequently Asked Questions

What is CVE-2026-100555? +
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. It has a CVSS v3.1 base score of 7.1 (HIGH).
How severe is CVE-2026-100555? +
CVE-2026-100555 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-100555? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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