CVE-2026-4957Public exploitNetwork attack vector

API key disclosure via unredacted tool arguments

Published Mar 27, 2026 · Updated Mar 27, 2026

Sensitive information exposure in OpenBMB XAgent 1.0.0 allows remote authenticated users to obtain plaintext API keys through tool calls. FunctionHandler.handle_tool_call logs the unredacted arguments dictionary and returns it as using_tools.tool_input, which is persisted and sent over the session WebSocket. An account that can submit a task must induce an API-key-accepting tool call; the consequence is disclosure of that tool's third-party credential.

CVSS severity2.7
Low
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sensitive information exposure in OpenBMB XAgent 1.0.0 allows remote authenticated users to obtain plaintext API keys through tool calls. FunctionHandler.handle_tool_call logs the unredacted arguments dictionary and returns it as using_tools.tool_input, which is persisted and sent over the session WebSocket. An account that can submit a task must induce an API-key-accepting tool call; the consequence is disclosure of that tool's third-party credential.

The record

CVE
CVE-2026-4957
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
OpenBMB
Product
XAgent
Classifications
CWE-200, CWE-532, T1552.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenBMB · XAgentversion=1.0.0

Published CVSS scores

3.3VulDBAV:N/AC:L/Au:M/C:P/I:N/A:N
2.0VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
2.7VulDBCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-532Insertion of Sensitive Information into Log File
T1552.001Unsecured Credentials: Credentials In Files

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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