Is CVE-2026-53839 in the CISA KEV catalog?

No. CVE-2026-53839 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-53839?

CVE-2026-53839 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2026-53839?

CVE-2026-53839 has an EPSS score of 0.27% (18th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-53839?

Upgrade openclaw to 2026.5.7 or later.

CVE & CISA-KEV Catalog

CVE-2026-53839

MEDIUM

6.5

CVSS v3

NVD

Description

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 host to send authentication material to untrusted endpoints.

CWE-1023

How to fix

Remediation Available

openclawNVD

Affected:< 2026.5.7Fixed in:2026.5.7CVE-2026-53839derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityNone

AvailabilityNone

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

Exploit Intelligence

0.27%probability of exploitation in 30 days

18thpercentile

Low risk: more likely to be exploited than 18% of all known CVEs.

References

Vendor Advisory1

github.com

Third-Party Advisory1

vulncheck.com

Embed a live status badge for CVE-2026-53839

Markdown

[![CVE-2026-53839](https://tridentstack.com/cve/badge/CVE-2026-53839.svg)](https://tridentstack.com/cve/CVE-2026-53839)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-53839"><img src="https://tridentstack.com/cve/badge/CVE-2026-53839.svg" alt="CVE-2026-53839"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-16.