{"id":"CVE-2026-35640","aliases":["EUVD-2026-21136","GHSA-3h52-cx59-c456","GHSA-8f9r-gr6r-x63q"],"status":"published","title":"OpenClaw \u003c 2026.3.25 - Denial of Service via Unauthenticated Webhook Request Parsing","description":"OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00453,"percentile":0.39606,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400","CWE-696"],"published":"2026-03-29T15:48:58Z","modified":"2026-10-28T02:31:10Z","fixes":[{"ecosystem":"npm","package":"openclaw","fixed_in":["2026.3.28"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"openclaw","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2026.3.28"}]}]},{"source":"osv","ecosystem":"npm","package":"openclaw","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2026.3.28"}]}]}],"products":[{"vendor":"openclaw","product":"openclaw"}],"references":[{"url":"https://github.com/openclaw/openclaw/security/advisories/GHSA-3h52-cx59-c456","tags":["vendor-advisory","Vendor Advisory","advisory","web"]},{"url":"https://github.com/openclaw/openclaw/commit/5e8cb22176e9235e224be0bc530699261eb60e53","tags":["patch","Patch","fix","web"]},{"url":"https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unauthenticated-webhook-request-parsing","tags":["third-party-advisory","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35640","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-3h52-cx59-c456"},{"url":"https://github.com/advisories/GHSA-8f9r-gr6r-x63q"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35640.json","tags":["advisory"]},{"url":"https://github.com/openclaw/openclaw","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-35640","title":"OpenClaw \u003c 2026.3.25 - Denial of Service via Unauthenticated Webhook Request Parsing","description":"OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.","status":"published","published":"2026-04-09T21:27:08.792Z","modified":"2026-06-23T16:16:00.938Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-696"],"updated_at":"2026-11-02T14:20:05.505362Z"}],"euvd":[{"id":"EUVD-2026-21136","description":"OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.","status":"published","published":"2026-04-09T21:27:08Z","modified":"2026-06-23T16:16:00Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:20:31.896888Z"}],"ghsa":[{"id":"GHSA-3h52-cx59-c456","title":"OpenClaw: Feishu webhook reads and parses unauthenticated request bodies before signature validation","description":"## Summary\n\nFeishu webhook reads and parses unauthenticated request bodies before signature validation\n\n## Affected Packages / Versions\n\n- Package: `openclaw`\n- Affected versions: `\u003c= 2026.3.24`\n- First patched version: `2026.3.25`\n- Latest published npm version at verification time: `2026.3.24`\n\n## Details\n\nFeishu webhook handling previously parsed JSON before signature validation, which let unauthenticated callers force full JSON parsing work before rejection. Commit `5e8cb22176e9235e224be0bc530699261eb60e53` reads the raw request body, validates the signature first, and only then parses JSON.\n\nVerified vulnerable on tag `v2026.3.24` and fixed on `main` by commit `5e8cb22176e9235e224be0bc530699261eb60e53`.\n\n## Fix Commit(s)\n\n- `5e8cb22176e9235e224be0bc530699261eb60e53`","status":"published","published":"2026-03-29T15:48:58Z","modified":"2026-04-10T20:21:38Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:39:53.087746Z"},{"id":"GHSA-8f9r-gr6r-x63q","title":"Duplicate Advisory: OpenClaw: Feishu webhook reads and parses unauthenticated request bodies before signature validation","description":"### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-3h52-cx59-c456. This link is maintained to preserve external references.\n\n### Original Description\nOpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.","status":"withdrawn","published":"2026-04-10T00:30:30Z","modified":"2026-04-10T20:21:23Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-696"],"updated_at":"2026-11-02T14:39:53.087746Z"}],"nvd":[{"id":"CVE-2026-35640","description":"OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.","status":"published","published":"2026-04-09T22:16:33.507Z","modified":"2026-06-17T10:40:56.503Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-696"],"updated_at":"2026-11-02T14:12:13.902911Z"}],"osv":[{"id":"CVE-2026-35640","title":"OpenClaw \u003c 2026.3.25 - Denial of Service via Unauthenticated Webhook Request Parsing","description":"OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.","status":"published","published":"2026-04-09T21:27:08.792Z","modified":"2026-10-28T02:31:10.625838275Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-696"],"updated_at":"2026-11-02T15:45:02.673625Z"},{"id":"GHSA-3h52-cx59-c456","title":"OpenClaw: Feishu webhook reads and parses unauthenticated request bodies before signature validation","description":"## Summary\n\nFeishu webhook reads and parses unauthenticated request bodies before signature validation\n\n## Affected Packages / Versions\n\n- Package: `openclaw`\n- Affected versions: `\u003c= 2026.3.24`\n- First patched version: `2026.3.25`\n- Latest published npm version at verification time: `2026.3.24`\n\n## Details\n\nFeishu webhook handling previously parsed JSON before signature validation, which let unauthenticated callers force full JSON parsing work before rejection. Commit `5e8cb22176e9235e224be0bc530699261eb60e53` reads the raw request body, validates the signature first, and only then parses JSON.\n\nVerified vulnerable on tag `v2026.3.24` and fixed on `main` by commit `5e8cb22176e9235e224be0bc530699261eb60e53`.\n\n## Fix Commit(s)\n\n- `5e8cb22176e9235e224be0bc530699261eb60e53`","status":"published","published":"2026-03-29T15:48:58Z","modified":"2026-04-10T20:42:17.774742Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:35.747385Z"},{"id":"GHSA-8f9r-gr6r-x63q","title":"Duplicate Advisory: OpenClaw: Feishu webhook reads and parses unauthenticated request bodies before signature validation","description":"### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-3h52-cx59-c456. This link is maintained to preserve external references.\n\n### Original Description\nOpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.","status":"withdrawn","published":"2026-04-10T00:30:30Z","modified":"2026-04-10T20:33:43.032381Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"},{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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"}],"cwes":["CWE-696"],"updated_at":"2026-11-02T15:46:42.437513Z"}]}}