CVE-2026-53859

Description

OpenClaw before 2026.5.26 contains a hostname validation vulnerability allowing attackers to bypass blocklist comparisons using trailing-dot notation in model or workspace-derived URLs. Attackers can exploit inconsistent hostname checks to reach destinations that operators intended to block through hostname policies.

CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0021

Probability of exploitation

0.11%

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)

CWE-1023 CWE-1023

Affected Products

Vendor	Product	Versions
openclaw	openclaw	< 2026.5.26
openclaw	openclaw	All
openclaw	openclaw	All

References

Advisories & Patches

https://github.com/openclaw/openclaw/security/advisories/GHSA-gxg4-2rrr-jhc7

Other References

https://www.vulncheck.com/advisories/openclaw-hostname-validation-bypass-via-trailing-dot-inconsistency

Frequently Asked Questions

What is CVE-2026-53859? +

OpenClaw before 2026.5.26 contains a hostname validation vulnerability allowing attackers to bypass blocklist comparisons using trailing-dot notation in model or workspace-derived URLs. Attackers can exploit inconsistent hostname checks to reach destinations that operators intended to block through hostname policies. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-53859? +

CVE-2026-53859 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0021, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-53859? +

CVE-2026-53859 affects products from openclaw, specifically: openclaw. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-53859? +

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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