CVE-2026-40518: ByteDance DeerFlow Path Traversal and Arbitrary File Write via Bootstrap Mode

Published Apr 17, 2026
·
Updated

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.

Affected Software

2 affected components
ByteDance DeerFlow<commit 2176b2b
ByteDance DeerFlow=2.0-m0

Event History

Apr 17, 2026
CVE Published
via MITRE·04:43 PM
Data Sourced
via MITRE·04:43 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:17 PM
RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-40518?

CVE-2026-40518 is categorized as a medium severity vulnerability due to its potential for unauthorized file writes.

2

How do I fix CVE-2026-40518?

To mitigate CVE-2026-40518, upgrade ByteDance DeerFlow to commit 2176b2b or later where the vulnerability is patched.

3

What is the impact of CVE-2026-40518?

CVE-2026-40518 allows attackers to exploit path traversal to write arbitrary files, potentially leading to data compromise.

4

Who is affected by CVE-2026-40518?

Users of ByteDance DeerFlow versions prior to commit 2176b2b are affected by CVE-2026-40518.

5

What kind of vulnerability is CVE-2026-40518?

CVE-2026-40518 is a path traversal and arbitrary file write vulnerability associated with bootstrap-mode custom-agent creation.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203