CVE-2026-31950Public exploitNetwork attack vector

Cross-user chat disclosure via unchecked stream ownership

Published Mar 27, 2026 · Updated Mar 27, 2026

Improper access control in LibreChat 0.8.2-rc2 through 0.8.2-rc3 allows remote authenticated users to read other users' live agent chats. The GET handler for /api/agents/chat/stream/:streamId retrieves a generation job but never compares job.metadata.userId with the authenticated user's ID before starting the SSE response. Exploitation requires agents to be enabled and a valid active random stream ID obtained through a secondary channel; access is read-only and exposes messages, AI responses, and tool invocations.

CVSS severity5.3
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in LibreChat 0.8.2-rc2 through 0.8.2-rc3 allows remote authenticated users to read other users' live agent chats. The GET handler for /api/agents/chat/stream/:streamId retrieves a generation job but never compares job.metadata.userId with the authenticated user's ID before starting the SSE response. Exploitation requires agents to be enabled and a valid active random stream ID obtained through a secondary channel; access is read-only and exposes messages, AI responses, and tool invocations.

The record

CVE
CVE-2026-31950
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
Danny Avila
Product
LibreChat
Classifications
CWE-639, CWE-284, T1213
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=>= 0.8.2-rc2, < 0.8.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Danny Avila · LibreChatversion=>= 0.8.2-rc2, < 0.8.2

Published CVSS scores

5.3GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-639Authorization Bypass Through User-Controlled Key
CWE-284Improper Access Control
T1213Data from Information Repositories

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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