LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats

Summary

CVECVE-2026-31950
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-27 20:16:30 UTC
Updated2026-03-30 20:32:16 UTC
DescriptionLibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc2 through 0.8.2-rc3, the SSE streaming endpoint `/api/agents/chat/stream/:streamId` does not verify that the requesting user owns the stream. Any authenticated user who obtains or guesses a valid stream ID can subscribe and read another user's real-time chat content, including messages, AI responses, and tool invocations. Version 0.8.2 patches the issue.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS: 0.000300000 probability, percentile 0.084270000 (date 2026-04-01)

Problem Types: CWE-284 | CWE-639 | CWE-284 CWE-284: Improper Access Control


VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.3MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Librechat Librechat 0.8.2 rc2 All All
Application Librechat Librechat 0.8.2 rc3 All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Danny-avila LibreChat affected >= 0.8.2-rc2, < 0.8.2 Not specified

References

ReferenceSourceLinkTags
github.com/danny-avila/LibreChat/security/advisories/GHSA-f6rf-vm44-wh5g [email protected] github.com Exploit, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
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