{"id":"CVE-2026-40518","aliases":["EUVD-2026-23456","GHSA-54pv-34f9-m4mq"],"status":"published","title":"ByteDance DeerFlow Path Traversal and Arbitrary File Write via Bootstrap Mode","description":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write vulnerability in bootstrap-mode custom-agent creation where the agent name validation is bypassed. Attackers can supply traversal-style values or absolute paths as the agent name to influence directory creation and write files outside the intended custom-agent directory, potentially achieving arbitrary file write on the system subject to filesystem permissions.","severity":{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00356,"percentile":0.29568,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-22"],"published":"2026-04-17T16:43:42Z","modified":"2026-11-09T02:47:24Z","products":[{"vendor":"bytedance","product":"deer-flow"},{"vendor":"bytedance","product":"deerflow"}],"references":[{"url":"https://github.com/bytedance/deer-flow/pull/2274","tags":["issue-tracking","patch","Issue Tracking","Patch","fix"]},{"url":"https://github.com/bytedance/deer-flow/commit/2176b2bbfccfce25ceee08318813f96d843a13fd","tags":["patch","Patch","fix"]},{"url":"https://www.vulncheck.com/advisories/bytedance-deerflow-path-traversal-and-arbitrary-file-write-via-bootstrap-mode","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40518","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-54pv-34f9-m4mq"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40518.json","tags":["advisory"]},{"url":"https://github.com/bytedance/deer-flow","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-40518","title":"ByteDance DeerFlow Path Traversal and Arbitrary File Write via Bootstrap Mode","description":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write vulnerability in bootstrap-mode custom-agent creation where the agent name validation is bypassed. Attackers can supply traversal-style values or absolute paths as the agent name to influence directory creation and write files outside the intended custom-agent directory, potentially achieving arbitrary file write on the system subject to filesystem permissions.","status":"published","published":"2026-04-17T16:43:42.387Z","modified":"2026-11-08T14:02:56.489Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-08T15:43:33.322657Z"}],"euvd":[{"id":"EUVD-2026-23456","description":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write vulnerability in bootstrap-mode custom-agent creation where the agent name validation is bypassed. Attackers can supply traversal-style values or absolute paths as the agent name to influence directory creation and write files outside the intended custom-agent directory, potentially achieving arbitrary file write on the system subject to filesystem permissions.","status":"published","published":"2026-04-17T16:43:42Z","modified":"2026-11-08T14:02:56Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-08T15:13:09.268962Z"}],"ghsa":[{"id":"GHSA-54pv-34f9-m4mq","title":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write...","description":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write vulnerability in bootstrap-mode custom-agent creation where the agent name validation is bypassed. Attackers can supply traversal-style values or absolute paths as the agent name to influence directory creation and write files outside the intended custom-agent directory, potentially achieving arbitrary file write on the system subject to filesystem permissions.","status":"published","published":"2026-04-17T18:31:53Z","modified":"2026-04-17T18:32:05Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/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":"high"},{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:07:32.404178Z"}],"nvd":[{"id":"CVE-2026-40518","description":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write vulnerability in bootstrap-mode custom-agent creation where the agent name validation is bypassed. Attackers can supply traversal-style values or absolute paths as the agent name to influence directory creation and write files outside the intended custom-agent directory, potentially achieving arbitrary file write on the system subject to filesystem permissions.","status":"published","published":"2026-04-17T17:17:09.543Z","modified":"2026-10-26T21:10:00.17Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/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":"high","assessor":"secondary"},{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:12:15.120927Z"}],"osv":[{"id":"CVE-2026-40518","title":"ByteDance DeerFlow Path Traversal and Arbitrary File Write via Bootstrap Mode","description":"ByteDance DeerFlow before commit 2176b2b contains a path traversal and arbitrary file write vulnerability in bootstrap-mode custom-agent creation where the agent name validation is bypassed. Attackers can supply traversal-style values or absolute paths as the agent name to influence directory creation and write files outside the intended custom-agent directory, potentially achieving arbitrary file write on the system subject to filesystem permissions.","status":"published","published":"2026-04-17T16:43:42.387Z","modified":"2026-11-09T02:47:24.764237273Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-09T03:16:17.543303Z"}]}}