{"id":"CVE-2026-53859","aliases":["EUVD-2026-37161","GHSA-gxg4-2rrr-jhc7","GHSA-vqx6-6j84-2794"],"status":"published","title":"OpenClaw \u003c 2026.5.26 - Hostname Validation Bypass via Trailing-Dot Inconsistency","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.","severity":{"version":"4.0","score":6,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0021,"percentile":0.11336,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1023","CWE-20","CWE-918"],"published":"2026-06-16T18:05:06Z","modified":"2026-10-28T02:30:22Z","fixes":[{"ecosystem":"npm","package":"openclaw","fixed_in":["2026.5.26"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"openclaw","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2026.5.22"},{"fixed":"2026.5.26"}]}]},{"source":"osv","ecosystem":"npm","package":"openclaw","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2026.5.26"}]}]}],"products":[{"vendor":"openclaw","product":"openclaw"}],"references":[{"url":"https://github.com/openclaw/openclaw/security/advisories/GHSA-gxg4-2rrr-jhc7","tags":["vendor-advisory","Vendor Advisory","Mitigation","advisory","web"]},{"url":"https://www.vulncheck.com/advisories/openclaw-hostname-validation-bypass-via-trailing-dot-inconsistency","tags":["third-party-advisory","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53859","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-gxg4-2rrr-jhc7"},{"url":"https://github.com/advisories/GHSA-vqx6-6j84-2794"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53859.json","tags":["advisory"]},{"url":"https://github.com/openclaw/openclaw","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-53859","title":"OpenClaw \u003c 2026.5.26 - Hostname Validation Bypass via Trailing-Dot Inconsistency","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.","status":"published","published":"2026-06-16T18:05:06.511Z","modified":"2026-06-16T18:38:58.295Z","cvss":[{"version":"4.0","score":6,"vector":"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","level":"medium","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-1023","CWE-918"],"updated_at":"2026-11-02T14:19:59.761005Z"}],"euvd":[{"id":"EUVD-2026-37161","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.","status":"published","published":"2026-06-16T18:05:06Z","modified":"2026-06-16T18:38:58Z","cvss":[{"version":"4.0","score":6,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T18:20:39.851172Z"}],"ghsa":[{"id":"GHSA-gxg4-2rrr-jhc7","title":"OpenClaw: Hostname checks could treat trailing-dot hosts inconsistently","description":"### Summary\n\nHostname checks could treat trailing-dot hosts inconsistently. In affected versions, a request path that accepts model- or workspace-derived URLs could present the same hostname with a trailing dot and avoid a blocklist comparison.\n\nThis advisory is scoped to the named feature and configuration. It does not change OpenClaw's trusted-operator model: authenticated Gateway operators, installed plugins, and intentional local execution surfaces remain trusted unless a separate policy, approval, allowlist, sandbox, or auth boundary is crossed.\n\n### Impact\n\nWhen the affected feature is enabled and reachable, this could reach a destination that the operator expected the hostname policy to block. Practical impact depends on the operator's configuration and whether lower-trust input can reach that path.\n\n### Patched Versions\n\nThe first stable patched version is `2026.5.26`.\n\n### Mitigations\n\nkeep private-network and metadata destinations blocked at the proxy or network layer until patched. As general hardening, keep channel and tool allowlists narrow, avoid sharing one Gateway between mutually untrusted users, and disable the affected feature when it is not needed.","status":"published","published":"2026-06-18T20:11:31Z","modified":"2026-06-18T20:11:33Z","cvss":[{"version":"4.0","score":6,"vector":"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","level":"medium"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-20","CWE-918"],"updated_at":"2026-11-02T14:40:29.43528Z"},{"id":"GHSA-vqx6-6j84-2794","title":"Duplicate Advisory: Hostname checks could treat trailing-dot hosts inconsistently","description":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-gxg4-2rrr-jhc7. This link is maintained to preserve external references.\n\n## Original Description\nOpenClaw 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.","status":"withdrawn","published":"2026-06-16T21:31:59Z","modified":"2026-06-18T20:11:23Z","cvss":[{"version":"4.0","score":6,"vector":"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","level":"medium"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:40:29.43528Z"}],"nvd":[{"id":"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.","status":"published","published":"2026-06-16T19:17:03.44Z","modified":"2026-06-17T22:12:00.27Z","cvss":[{"version":"4.0","score":6,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-918","CWE-1023"],"updated_at":"2026-11-02T14:12:24.19758Z"}],"osv":[{"id":"CVE-2026-53859","title":"OpenClaw \u003c 2026.5.26 - Hostname Validation Bypass via Trailing-Dot Inconsistency","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.","status":"published","published":"2026-06-16T18:05:06.511Z","modified":"2026-10-28T02:30:22.792958427Z","cvss":[{"version":"4.0","score":6,"vector":"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","level":"medium"}],"cwes":["CWE-1023","CWE-918"],"updated_at":"2026-11-02T15:45:08.132336Z"},{"id":"GHSA-gxg4-2rrr-jhc7","title":"OpenClaw: Hostname checks could treat trailing-dot hosts inconsistently","description":"### Summary\n\nHostname checks could treat trailing-dot hosts inconsistently. In affected versions, a request path that accepts model- or workspace-derived URLs could present the same hostname with a trailing dot and avoid a blocklist comparison.\n\nThis advisory is scoped to the named feature and configuration. It does not change OpenClaw's trusted-operator model: authenticated Gateway operators, installed plugins, and intentional local execution surfaces remain trusted unless a separate policy, approval, allowlist, sandbox, or auth boundary is crossed.\n\n### Impact\n\nWhen the affected feature is enabled and reachable, this could reach a destination that the operator expected the hostname policy to block. Practical impact depends on the operator's configuration and whether lower-trust input can reach that path.\n\n### Patched Versions\n\nThe first stable patched version is `2026.5.26`.\n\n### Mitigations\n\nkeep private-network and metadata destinations blocked at the proxy or network layer until patched. As general hardening, keep channel and tool allowlists narrow, avoid sharing one Gateway between mutually untrusted users, and disable the affected feature when it is not needed.","status":"published","published":"2026-06-18T20:11:31Z","modified":"2026-06-18T20:26:32.057864Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"},{"version":"4.0","score":6,"vector":"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","level":"medium"}],"cwes":["CWE-20","CWE-918"],"updated_at":"2026-11-02T15:46:48.546324Z"},{"id":"GHSA-vqx6-6j84-2794","title":"Duplicate Advisory: Hostname checks could treat trailing-dot hosts inconsistently","description":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-gxg4-2rrr-jhc7. This link is maintained to preserve external references.\n\n## Original Description\nOpenClaw 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.","status":"withdrawn","published":"2026-06-16T21:31:59Z","modified":"2026-06-18T20:15:17.327175917Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"},{"version":"4.0","score":6,"vector":"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","level":"medium"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:46:57.694388Z"}]}}