Auth bypass in Openbmb Xagent
CVE-2026-4959
A vulnerability was found in OpenBMB XAgent 1.0.0. This impacts the function check_user of the file XAgentServer/application/websockets/share.py of the component ShareServer WebSocket Endpoint. Performing a manipulation of the argument interaction_id results in missing authentication. Remote exploitation of the attack is possible. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.008 (53.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.008 · change: +0.003
Affected products
- Openbmb Xagent — versions 1.0.0
Weakness classification (CWE)
References
- vuldb.com/ (Permissions Required, technical-description, VDB Entry, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/ (Third Party Advisory, Issue Tracking, third-party-advisory)
- gist.github.com/YLChen-007/531ec6b169f4b9ecbc8c2f0b2cd7c5ee (Exploit, Third Party Advisory, exploit)
Frequently asked questions
- What is CVE-2026-4959?
- CVE-2026-4959 is a high-severity vulnerability in Openbmb Xagent, classified under Improper Authentication. CVSS score: 7.3/10. Published 2026-03-27.
- How severe is CVE-2026-4959?
- High severity. CVSS v3 base score is 7.3 out of 10.