CVE-2026-40518CWE-22

ByteDance DeerFlow Path Traversal and Arbitrary File Write via Bootstrap Mode

High · published April 17, 2026

CVSS v4.0
7.1
EPSS
1%
Percentile
45.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
7.1 · HIGH
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
EPSS
0.00549 · 45.2th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-04-17T16:43Z
EPSS history
Timeline
  • 17 APR 16:43Z
    ByteDance DeerFlow Path Traversal and Arbitrary File Write via Bootstrap Mode
    cvelistv5