Path Traversal in Openbmb Chatdev

CVE-2026-58166

OpenBMB ChatDev through 2.2.0, fixed in commit 4fd4da6, contains a path traversal vulnerability that allows unauthenticated remote attackers to write or delete arbitrary files by supplying a malicious multipart filename in the file upload endpoint. Attackers can send a crafted filename containing path traversal sequences or an absolute path to the POST uploads session endpoint, which constructs the destination path without sanitization in save_upload_file, causing file write and cleanup operations to target attacker-chosen paths on the server filesystem.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (56.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-58166: held from 0.009 to 0.009.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-58166?
CVE-2026-58166 is a critical-severity vulnerability in Openbmb Chatdev, classified under Path Traversal. CVSS score: 9.1/10. Published 2026-06-30.
How severe is CVE-2026-58166?
Critical severity. CVSS v3 base score is 9.1 out of 10.