What is CVE-2026-53839?

CVE-2026-53839 is a medium-severity vulnerability in Openclaw, classified under CWE-1023. CVSS score: 6.5/10. Published 2026-06-12.

How severe is CVE-2026-53839?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Openclaw

CVE-2026-53839

OpenClaw before 2026.5.7 contains a hostname validation vulnerability in retry endpoint checks that allows matching hostname prefixes instead of exact hostnames. Attackers can exploit this by crafting a hostname prefix resembling a trusted…

EPSS: 0.003 (18.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Openclaw — versions 0, 2026.5.7

Weakness classification (CWE)

CWE-1023

References

disclosure@vulncheck.com (vendor-advisory, Mitigation, Vendor Advisory)
disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-53839?: CVE-2026-53839 is a medium-severity vulnerability in Openclaw, classified under CWE-1023. CVSS score: 6.5/10. Published 2026-06-12.
How severe is CVE-2026-53839?: Medium severity. CVSS v3 base score is 6.5 out of 10.