Path Traversal in Bytedance Deer-flow

CVE-2026-40518

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 a…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.000 (14.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40518?
CVE-2026-40518 is a high-severity vulnerability in Bytedance Deer-flow, classified under Path Traversal. CVSS score: 7.1/10. Published 2026-04-17.
How severe is CVE-2026-40518?
High severity. CVSS v3 base score is 7.1 out of 10.