Summaryinfo

A vulnerability described as critical has been identified in Bytedance DeerFlow. Affected by this issue is some unknown functionality. Such manipulation leads to incomplete blacklist. This vulnerability is traded as CVE-2026-34430. The attack may be launched remotely. There is no exploit available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Bytedance DeerFlow (unknown version). Affected by this issue is an unknown code block. The manipulation with an unknown input leads to a incomplete blacklist vulnerability. Using CWE to declare the problem leads to CWE-184. The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete, leading to resultant weaknesses. Impacted is confidentiality, integrity, and availability. CVE summarizes:

ByteDance Deer-Flow versions prior to commit 92c7a20 contain a sandbox escape vulnerability in bash tool handling that allows attackers to execute arbitrary commands on the host system by bypassing regex-based validation using shell features such as directory changes and relative paths. Attackers can exploit the incomplete shell semantics modeling to read and modify files outside the sandbox boundary and achieve arbitrary command execution through subprocess invocation with shell interpretation enabled.

The weakness was shared by Chia Min Jun Lennon. The advisory is available at github.com. This vulnerability is handled as CVE-2026-34430 since 03/27/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1562.006 by the MITRE ATT&CK project.

Applying the patch 92c7a20cb74addc3038d2131da78f2e239ef542e is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-17903). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• Bytedance

Name

• DeerFlow

License

• open-source

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion