{"id":"CVE-2026-28394","aliases":["EUVD-2026-9894","GHSA-p536-vvpp-9mc8"],"status":"published","title":"OpenClaw \u003c 2026.2.15 - Denial of Service via Unbounded Response Parsing in web_fetch Tool","description":"OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00462,"percentile":0.40547,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400","CWE-770"],"published":"2026-02-19T19:40:56Z","modified":"2026-11-04T02:51:07Z","fixes":[{"ecosystem":"npm","package":"openclaw","fixed_in":["2026.2.15"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"openclaw","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2026.2.15"}]}]},{"source":"osv","ecosystem":"npm","package":"openclaw","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2026.2.15"}]}]}],"products":[{"vendor":"openclaw","product":"openclaw"}],"references":[{"url":"https://github.com/openclaw/openclaw/security/advisories/GHSA-p536-vvpp-9mc8","tags":["vendor-advisory","Vendor Advisory","advisory","web"]},{"url":"https://github.com/openclaw/openclaw/commit/166cf6a3e04c7df42bea70a7ad5ce2b9df46d147","tags":["patch","Patch","fix","web"]},{"url":"https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unbounded-response-parsing-in-web-fetch-tool","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://github.com/openclaw/openclaw/releases/tag/v2026.2.15","tags":["web"]},{"url":"https://github.com/advisories/GHSA-p536-vvpp-9mc8"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/28xxx/CVE-2026-28394.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28394","tags":["advisory"]},{"url":"https://github.com/openclaw/openclaw","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-28394","title":"OpenClaw \u003c 2026.2.15 - Denial of Service via Unbounded Response Parsing in web_fetch Tool","description":"OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.","status":"published","published":"2026-03-05T21:59:22.734Z","modified":"2026-03-11T13:35:37.639Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/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:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:20:01.969981Z"}],"euvd":[{"id":"EUVD-2026-9894","description":"OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.","status":"published","published":"2026-03-05T21:59:22Z","modified":"2026-03-11T13:35:37Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:25:37.650533Z"}],"ghsa":[{"id":"GHSA-p536-vvpp-9mc8","title":"OpenClaw has a Web Fetch DoS via unbounded response parsing","description":"### Summary\nThe `web_fetch` tool could be used to crash the OpenClaw Gateway process (OOM / resource exhaustion) by fetching and attempting to parse attacker-controlled web pages with oversized response bodies or pathological HTML nesting.\n\n### Affected Packages / Versions\n- Package: `openclaw` (npm)\n- Affected versions: `\u003c= 2026.2.14`\n- Fixed versions: `\u003e= 2026.2.15`\n\n### Impact\nAn attacker can social-engineer a user (or any automation that uses `web_fetch`) into fetching a malicious URL that returns extremely large or deeply nested HTML. The Gateway may exhaust memory or become unresponsive, causing a denial of service.\n\n### Fix\nThe Gateway now caps the downloaded response body size before any HTML parsing and adds additional guards to avoid running Readability/DOM parsing on pathological HTML.\n\n### Fix Commit(s)\n- 166cf6a3e04c7df42bea70a7ad5ce2b9df46d147\n\n### Release Process Note\nThis advisory is prepared for the next npm release. Once `openclaw@2026.2.15` is published, publish this advisory without further edits.\n\nThanks @xuemian168 for reporting.","status":"published","published":"2026-02-19T19:40:56Z","modified":"2026-03-05T21:42:22Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:39:31.060223Z"}],"nvd":[{"id":"CVE-2026-28394","description":"OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.","status":"published","published":"2026-03-05T22:16:15.973Z","modified":"2026-06-17T10:28:32.523Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/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:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:07.852448Z"}],"osv":[{"id":"CVE-2026-28394","title":"OpenClaw \u003c 2026.2.15 - Denial of Service via Unbounded Response Parsing in web_fetch Tool","description":"OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.","status":"published","published":"2026-03-05T21:59:22.734Z","modified":"2026-11-04T02:51:07.023003708Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-04T03:25:28.514393Z"},{"id":"GHSA-p536-vvpp-9mc8","title":"OpenClaw has a Web Fetch DoS via unbounded response parsing","description":"### Summary\nThe `web_fetch` tool could be used to crash the OpenClaw Gateway process (OOM / resource exhaustion) by fetching and attempting to parse attacker-controlled web pages with oversized response bodies or pathological HTML nesting.\n\n### Affected Packages / Versions\n- Package: `openclaw` (npm)\n- Affected versions: `\u003c= 2026.2.14`\n- Fixed versions: `\u003e= 2026.2.15`\n\n### Impact\nAn attacker can social-engineer a user (or any automation that uses `web_fetch`) into fetching a malicious URL that returns extremely large or deeply nested HTML. The Gateway may exhaust memory or become unresponsive, causing a denial of service.\n\n### Fix\nThe Gateway now caps the downloaded response body size before any HTML parsing and adds additional guards to avoid running Readability/DOM parsing on pathological HTML.\n\n### Fix Commit(s)\n- 166cf6a3e04c7df42bea70a7ad5ce2b9df46d147\n\n### Release Process Note\nThis advisory is prepared for the next npm release. Once `openclaw@2026.2.15` is published, publish this advisory without further edits.\n\nThanks @xuemian168 for reporting.","status":"published","published":"2026-02-19T19:40:56Z","modified":"2026-03-05T22:11:21.125125Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:52.534897Z"}]}}