SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

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.

HIGH 8.8EPSS 0.85%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.85%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0
8.8 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.85% probability · 56th percentile
CISA KEV
Not listed
Weakness
CWE-22
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.