CVE-2026-31944
highpriority · track · 0OT risk · elevatedEPSS 0.003 · 17 %ileEURUUSEPSS · scored 2026-10-27
LibreChat is a ChatGPT clone with additional features. From 0.8.2 to 0.8.2-rc3, The MCP (Model Context Protocol) OAuth callback endpoint accepts the redirect from the identity provider and stores OAuth tokens for the user who initiated the flow, without verifying that the browser hitting the redirect URL is logged in or that the logged-in user matches the initiator. An attacker can send the authorization URL to a victim; when the victim completes the flow, the victim’s OAuth tokens are stored on the attacker’s LibreChat account, enabling account takeover of the victim’s MCP-linked services (e.g. Atlassian, Outlook). This vulnerability is fixed in 0.8.3-rc1.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (4)
External citations — patches, advisories, analysis.
- https://github.com/danny-avila/LibreChat/security/advisories/GHSA-vf7j-7mrx-hp7gcnnvd
- https://www.librechat.ai/Patchcnnvd
- https://github.com/danny-avila/LibreChat/security/advisories/GHSA-vf7j-7mrx-hp7genisa_euvd
- https://github.com/danny-avila/LibreChat/security/advisories/GHSA-vf7j-7mrx-hp7gExploitVendor Advisorynvd
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