Auth bypass in Openbmb Xagent
CVE-2026-4958
A vulnerability has been found in OpenBMB XAgent 1.0.0. This affects the function ReplayServer.on_connect/ReplayServer.send_data of the file XAgentServer/application/websockets/replayer.py of the component WebSocket Endpoint. Such manipulation of the argument interaction_id leads to authorization bypass. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is reported as difficult. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (40.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.8% 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: 0.005 · change: +0.001
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/dc46c2a710ecb9e855695f32da8bcab5 (Exploit, Third Party Advisory, exploit)
Frequently asked questions
- What is CVE-2026-4958?
- CVE-2026-4958 is a low-severity vulnerability in Openbmb Xagent, classified under Improper Authorization. CVSS score: 3.1/10. Published 2026-03-27.
- How severe is CVE-2026-4958?
- Low severity. CVSS v3 base score is 3.1 out of 10.