PT-2026-33466 · Bytedance · Deer-Flow

Published 2026-04-17 · Updated 2026-04-17 · CVE-2026-40518

NVD

CVSS v3.1

7.1

High

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

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.

Fix

Path traversal

Weakness Enumeration

CWE-22

Related Identifiers

CVE-2026-40518

Affected Products

Deer-Flow

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2026-40518 · Security Note
• https://github.com/bytedance/deer-flow/commit/2176b2bbfccfce25ceee08318813f96d843a13fd · Patch
• https://vulncheck.com/advisories/bytedance-deerflow-path-traversal-and-arbitrary-file-write-via-bootstrap-mode · Note
• https://twitter.com/VulmonFeeds/status/2045237546515349869 · Twitter Post
• https://github.com/bytedance/deer-flow/pull/2274 · Note