# CVE-2026-51860: bisheng directory traversal in task_exec and cache utilities

Source: https://junglewise.ai/threats/cve-2026-51860-bisheng-2-3-0-2-4-0-and-2-4-0-beta1-is-vulnerable-to-directory  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-30. Updated: 2026-09-30  
License: CC BY 4.0 with a link back

CVE-2026-51860 · Severity: info · Published 2026-09-30

bisheng is a data processing and workflow orchestration platform. An attacker can exploit directory traversal vulnerabilities in file upload and download handlers to write files outside intended directories, potentially allowing arbitrary file creation, code execution, or data exfiltration on the server hosting bisheng.

Technologies: [Dataelement BISHENG](https://junglewise.ai/threats/technologies/bisheng). Vendors: [Dataelement](https://junglewise.ai/threats/vendors/dataelement).

## Quick answers

**Is CVE-2026-51860 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-51860 being exploited in the wild.

**How severe is CVE-2026-51860?** Informational severity, published 30 September 2026.

**Which products and versions are affected?** Dataelement BISHENG 2.3.0, 2.4.0, 2.4.0-beta1.

**Is there a fix for CVE-2026-51860?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-51860 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-51860?** Check whether you run Dataelement BISHENG at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

Two separate path traversal vulnerabilities exist: (1) in save_download_file (src/backend/bisheng/core/cache/utils.py) where user-supplied filenames are concatenated without validation, and (2) in _download_file (src/backend/bisheng/linsight/domain/task_exec.py) where file_name from workflow configuration is directly joined with target_dir using os.path.join(). Both allow traversal sequences like ../../ to escape the intended cache/target directory. These are reachable via the knowledgeUpload HTTP endpoint and Linsight workflow file downloads, requiring network access but no authentication or user interaction beyond API calls.

## Affected products

- dataelement bisheng 2.3.0, 2.4.0, 2.4.0-beta1

## Timeline

- 2026-09-30: disclosed: CVE-2026-51860 published on NVD
- 2026-04-20: other: Issues reported on GitHub (dataelement/bisheng#1994)

## References

- [https://gist.github.com/Ro1ME/e4129afdd9af2ff1bdcecf27ec5098cf](https://gist.github.com/Ro1ME/e4129afdd9af2ff1bdcecf27ec5098cf)
- [https://github.com/dataelement/bisheng/issues/1994](https://github.com/dataelement/bisheng/issues/1994)

## Related threats

- [BISHENG insecure direct object reference in knowledge file API](https://junglewise.ai/threats/cve-2026-111363-bisheng-through-3-0-0-beta4-contains-an-insecure-direct-object)
- [bisheng code injection in validate.py](https://junglewise.ai/threats/cve-2026-51861-bisheng-2-3-0-2-4-0-and-2-4-0-beta1-is-vulnerable-to-code)
- [bisheng directory traversal in save_download_file](https://junglewise.ai/threats/cve-2026-51859-bisheng-2-3-0-2-4-0-and-2-4-0-beta1-is-vulnerable-to-directory)
- [BISHENG server-side request forgery in workflow callback API](https://junglewise.ai/threats/cve-2026-82285-bisheng-server-side-request-forgery-in-workflow-callback-api)
- [DataElement BISHENG remote code execution in workflow run_once](https://junglewise.ai/threats/cve-2026-82278-dataelement-bisheng-remote-code-execution-in-workflow-run-once)