CVE-2026-53859 | OpenClaw before 2026.5.26 contains a hostname validation vul… | CVSS 6.5 MEDIUM

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.

Metadata

CVE ID: CVE-2026-53859
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-10 21:22 UTC
Published: 2026-06-16 18:05 UTC
Last updated: 2026-06-16 18:38 UTC
Primary CWE: CWE-1023
Incomplete Comparison with Missing Factors
Vendor / Product: OpenClaw / OpenClaw
Sources: cve.org · NVD

Severity & Metrics

6.5 MEDIUM CVSS 3.1

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

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
OpenClaw	OpenClaw	—	0 < 2026.5.26, 2026.5.26

Weakness (CWE)

CWE	Source	Description
CWE-1023	cna	Incomplete Comparison with Missing Factors
CWE-918	cna	Server-Side Request Forgery (SSRF)

CVSS scores (2)

Score	Severity	Version	Source	Vector
6.5	MEDIUM	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
6.0	MEDIUM	4.0	cna	CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References (2)

GitHub Security Advisory (GHSA-gxg4-2rrr-jhc7) https://github.com/openclaw/openclaw/security/advisories/GHSA-gxg4-2rrr-jhc7
VulnCheck Advisory: OpenClaw < 2026.5.26 - Hostname Validation Bypass via Trailing-Dot Inconsistency https://www.vulncheck.com/advisories/openclaw-hostname-validation-bypass-via-trailing-dot-inconsistency