{"id":"CVE-2026-29609","aliases":["EUVD-2026-9933","GHSA-j27p-hq53-9wgc"],"status":"published","title":"OpenClaw \u003c 2026.2.14 - Denial of Service via Unbounded URL-backed Media Fetch","description":"OpenClaw versions prior to 2026.2.14 contain a denial of service vulnerability in the fetchWithGuard function that allocates entire response payloads in memory before enforcing maxBytes limits. Remote attackers can trigger memory exhaustion by serving oversized responses without content-length headers to cause availability loss.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00485,"percentile":0.42269,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400","CWE-770"],"published":"2026-02-18T00:51:37Z","modified":"2026-10-28T02:31:14Z","fixes":[{"ecosystem":"npm","package":"openclaw","fixed_in":["2026.2.14"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"openclaw","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2026.2.14"}]}]},{"source":"osv","ecosystem":"npm","package":"openclaw","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2026.2.14"}]}]}],"products":[{"vendor":"openclaw","product":"openclaw"}],"references":[{"url":"https://github.com/openclaw/openclaw/security/advisories/GHSA-j27p-hq53-9wgc","tags":["vendor-advisory","exploit","Vendor Advisory","advisory","web"]},{"url":"https://github.com/openclaw/openclaw/commit/00a08908892d1743d1fc52e5cbd9499dd5da2fe0","tags":["patch","Patch","fix","web"]},{"url":"https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unbounded-url-backed-media-fetch","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://github.com/advisories/GHSA-j27p-hq53-9wgc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29609.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-29609","tags":["advisory"]},{"url":"https://github.com/openclaw/openclaw","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-29609","title":"OpenClaw \u003c 2026.2.14 - Denial of Service via Unbounded URL-backed Media Fetch","description":"OpenClaw versions prior to 2026.2.14 contain a denial of service vulnerability in the fetchWithGuard function that allocates entire response payloads in memory before enforcing maxBytes limits. Remote attackers can trigger memory exhaustion by serving oversized responses without content-length headers to cause availability loss.","status":"published","published":"2026-03-05T22:00:06.574Z","modified":"2026-03-09T20:37:30.422Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"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":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:19:56.284359Z"}],"euvd":[{"id":"EUVD-2026-9933","description":"OpenClaw versions prior to 2026.2.14 contain a denial of service vulnerability in the fetchWithGuard function that allocates entire response payloads in memory before enforcing maxBytes limits. Remote attackers can trigger memory exhaustion by serving oversized responses without content-length headers to cause availability loss.","status":"published","published":"2026-03-05T22:00:06Z","modified":"2026-03-09T20:37:30Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T19:48:06.014236Z"}],"ghsa":[{"id":"GHSA-j27p-hq53-9wgc","title":"OpenClaw affected by denial of service via unbounded URL-backed media fetch","description":"### Summary\nURL-backed media fetch handling allocated the entire response payload in memory (`arrayBuffer`) before enforcing `maxBytes`, allowing oversized responses to cause memory exhaustion.\n\n### Affected Versions\n- `openclaw` (npm): \u003c `2026.2.14`\n- `clawdbot` (npm): \u003c= `2026.1.24-3`\n\n### Patched Versions\n- `openclaw` (npm): `2026.2.14`\n\n### Fix Commit\n- `openclaw/openclaw` `main`: `00a08908892d1743d1fc52e5cbd9499dd5da2fe0`\n\n### Details\nAffected component:\n- `src/media/input-files.ts` (`fetchWithGuard`)\n\nWhen `content-length` is missing or incorrect, reading the body via `response.arrayBuffer()` buffers the full payload before a size check can run.\n\n### Proof of Concept\n1. Configure URL-based media input.\n2. Serve a response larger than `maxBytes` (chunked transfer / no `content-length`).\n3. Trigger the `fetchWithGuard` URL fetch path.\n\nExample local server (large response):\n```bash\nnode -e 'require(\"http\").createServer((_,res)=\u003e{res.writeHead(200,{\"content-type\":\"application/octet-stream\"});for(let i=0;i\u003c1024;i++)res.write(Buffer.alloc(1024*64));res.end();}).listen(18888)'\n```\n\n### Impact\nAvailability loss via memory pressure from attacker-controlled remote media responses.\n\n### Mitigation\nUntil a patched release is available, disable URL-backed media inputs (or restrict to a tight hostname allowlist) and use conservative `maxBytes` limits.\n\n### Credits\nReported by @vincentkoc.","status":"published","published":"2026-02-18T00:51:37Z","modified":"2026-03-05T21:59:52Z","cvss":[{"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"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:39:31.060223Z"}],"nvd":[{"id":"CVE-2026-29609","description":"OpenClaw versions prior to 2026.2.14 contain a denial of service vulnerability in the fetchWithGuard function that allocates entire response payloads in memory before enforcing maxBytes limits. Remote attackers can trigger memory exhaustion by serving oversized responses without content-length headers to cause availability loss.","status":"published","published":"2026-03-05T22:16:24.043Z","modified":"2026-06-17T10:29:49.353Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/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":"high","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":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:07.852448Z"}],"osv":[{"id":"CVE-2026-29609","title":"OpenClaw \u003c 2026.2.14 - Denial of Service via Unbounded URL-backed Media Fetch","description":"OpenClaw versions prior to 2026.2.14 contain a denial of service vulnerability in the fetchWithGuard function that allocates entire response payloads in memory before enforcing maxBytes limits. Remote attackers can trigger memory exhaustion by serving oversized responses without content-length headers to cause availability loss.","status":"published","published":"2026-03-05T22:00:06.574Z","modified":"2026-10-28T02:31:14.586980495Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:45:00.530889Z"},{"id":"GHSA-j27p-hq53-9wgc","title":"OpenClaw affected by denial of service via unbounded URL-backed media fetch","description":"### Summary\nURL-backed media fetch handling allocated the entire response payload in memory (`arrayBuffer`) before enforcing `maxBytes`, allowing oversized responses to cause memory exhaustion.\n\n### Affected Versions\n- `openclaw` (npm): \u003c `2026.2.14`\n- `clawdbot` (npm): \u003c= `2026.1.24-3`\n\n### Patched Versions\n- `openclaw` (npm): `2026.2.14`\n\n### Fix Commit\n- `openclaw/openclaw` `main`: `00a08908892d1743d1fc52e5cbd9499dd5da2fe0`\n\n### Details\nAffected component:\n- `src/media/input-files.ts` (`fetchWithGuard`)\n\nWhen `content-length` is missing or incorrect, reading the body via `response.arrayBuffer()` buffers the full payload before a size check can run.\n\n### Proof of Concept\n1. Configure URL-based media input.\n2. Serve a response larger than `maxBytes` (chunked transfer / no `content-length`).\n3. Trigger the `fetchWithGuard` URL fetch path.\n\nExample local server (large response):\n```bash\nnode -e 'require(\"http\").createServer((_,res)=\u003e{res.writeHead(200,{\"content-type\":\"application/octet-stream\"});for(let i=0;i\u003c1024;i++)res.write(Buffer.alloc(1024*64));res.end();}).listen(18888)'\n```\n\n### Impact\nAvailability loss via memory pressure from attacker-controlled remote media responses.\n\n### Mitigation\nUntil a patched release is available, disable URL-backed media inputs (or restrict to a tight hostname allowlist) and use conservative `maxBytes` limits.\n\n### Credits\nReported by @vincentkoc.","status":"published","published":"2026-02-18T00:51:37Z","modified":"2026-07-08T08:14:43.749135701Z","cvss":[{"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"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:49.621585Z"}]}}