CVE-2026-31944

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Source

https://cve.org/CVERecord?id=CVE-2026-31944

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31944.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-31944

Aliases

GHSA-vf7j-7mrx-hp7g

Published

2026-03-13T19:44:30.850Z

Modified

2026-07-15T01:49:12.672336045Z

Severity

7.6 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N CVSS Calculator

Summary

LibreChat MCP OAuth callback does not validate browser session — allows token theft via redirect link

Details

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.

Database specific

{
    "cna_assigner": "GitHub_M",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31944.json",
    "cwe_ids": [
        "CWE-306"
    ]
}

References

Affected packages

Git / github.com/danny-avila/librechat

Affected ranges

Type

GIT

Repo

https://github.com/danny-avila/librechat

Events

Introduced

efbc088642afb69540efae9518b66e07760b23b7

Last affected

b70528f59aca7b64d39027a36d970e57cc96158b

Database specific

{
    "cpe": [
        "cpe:2.3:a:librechat:librechat:0.8.2:-:*:*:*:*:*:*",
        "cpe:2.3:a:librechat:librechat:0.8.2:rc1:*:*:*:*:*:*",
        "cpe:2.3:a:librechat:librechat:0.8.2:rc2:*:*:*:*:*:*",
        "cpe:2.3:a:librechat:librechat:0.8.2:rc3:*:*:*:*:*:*"
    ],
    "extracted_events": [
        {
            "introduced": "v0.8.2"
        },
        {
            "last_affected": "0.8.2-rc3"
        },
        {
            "introduced": "0.8.2-NA"
        },
        {
            "last_affected": "0.8.2-NA"
        },
        {
            "introduced": "0.8.2-rc1"
        },
        {
            "last_affected": "0.8.2-rc1"
        },
        {
            "introduced": "0.8.2-rc2"
        },
        {
            "last_affected": "0.8.2-rc2"
        },
        {
            "introduced": "0.8.2-rc3"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "CPE_STRING"
    ]
}

Affected versions

0.*

0.8.2-NA

0.8.2-rc1

0.8.2-rc2

0.8.2-rc3

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31944.json"