VulnerabilityAnalyzed

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.

MEDIUM 6.0EPSS 0.27%

Does this matter?

Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.0 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.27% probability · 18th percentile
CISA KEV: Not listed
Weakness: CWE-1023
Affected: openclaw/openclaw
Source: disclosure@vulncheck.com

References

https://github.com/openclaw/openclaw/security/advisories/GHSA-77q5-rr5v-x43qMitigation, Vendor Advisory
https://www.vulncheck.com/advisories/openclaw-hostname-prefix-matching-bypass-in-trusted-retry-endpoint-validationThird Party Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.