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 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.

CVSS v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/bytedance/deer-flow/commit/2176b2bbfccfce25ceee08318813f96d843a13fd	Patch
https://github.com/bytedance/deer-flow/pull/2274	Issue Tracking Patch
https://www.vulncheck.com/advisories/bytedance-deerflow-path-traversal-and-arbitrary-file-write-via-bootstrap-mode	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:bytedance:deerflow:2.0-m0:*:*:*:*:*:*:*

History

05 Jun 2026, 18:07

Type	Values Removed	Values Added
CPE		cpe:2.3:a:bytedance:deerflow:2.0-m0:::::::*
First Time		Bytedance deerflow Bytedance
References	~~() https://github.com/bytedance/deer-flow/commit/2176b2bbfccfce25ceee08318813f96d843a13fd -~~	() https://github.com/bytedance/deer-flow/commit/2176b2bbfccfce25ceee08318813f96d843a13fd - Patch
References	~~() https://github.com/bytedance/deer-flow/pull/2274 -~~	() https://github.com/bytedance/deer-flow/pull/2274 - Issue Tracking, Patch
References	~~() https://www.vulncheck.com/advisories/bytedance-deerflow-path-traversal-and-arbitrary-file-write-via-bootstrap-mode -~~	() https://www.vulncheck.com/advisories/bytedance-deerflow-path-traversal-and-arbitrary-file-write-via-bootstrap-mode - Third Party Advisory

17 Apr 2026, 17:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-17 17:17

Updated : 2026-06-05 18:07

NVD link : CVE-2026-40518

Mitre link : CVE-2026-40518

CVE.ORG link : CVE-2026-40518

JSON object : View

Products Affected

bytedance

deerflow

CWE

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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