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Vulnerability Details :

CVE-2026-31944

Summary
Assigner-GitHub_M
Assigner Org ID-a0819718-46f1-4df5-94e2-005712e83aaa
Published At-13 Mar, 2026 | 19:44
Updated At-16 Mar, 2026 | 13:41
Rejected At-
Credits

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

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.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
▼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:GitHub_M
Assigner Org ID:a0819718-46f1-4df5-94e2-005712e83aaa
Published At:13 Mar, 2026 | 19:44
Updated At:16 Mar, 2026 | 13:41
Rejected At:
▼CVE Numbering Authority (CNA)
LibreChat MCP OAuth callback does not validate browser session — allows token theft via redirect link

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.

Affected Products
Vendor
danny-avila
Product
LibreChat
Versions
Affected
  • >= v0.8.2, <= 0.8.2-rc3
Problem Types
TypeCWE IDDescription
CWECWE-306CWE-306: Missing Authentication for Critical Function
Type: CWE
CWE ID: CWE-306
Description: CWE-306: Missing Authentication for Critical Function
Metrics
VersionBase scoreBase severityVector
3.17.6HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
Version: 3.1
Base score: 7.6
Base severity: HIGH
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
https://github.com/danny-avila/LibreChat/security/advisories/GHSA-vf7j-7mrx-hp7g
x_refsource_CONFIRM
Hyperlink: https://github.com/danny-avila/LibreChat/security/advisories/GHSA-vf7j-7mrx-hp7g
Resource:
x_refsource_CONFIRM
▼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions

Configurations

Workarounds

Exploits

Credits

Timeline
EventDate
Replaced By

Rejected Reason

References
HyperlinkResource
Information is not available yet
▼National Vulnerability Database (NVD)
nvd.nist.gov
Source:security-advisories@github.com
Published At:13 Mar, 2026 | 19:54
Updated At:17 Mar, 2026 | 12:39

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.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary3.17.6HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
Type: Secondary
Version: 3.1
Base score: 7.6
Base severity: HIGH
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
CPE Matches

librechat
librechat
>>librechat>>0.8.2
cpe:2.3:a:librechat:librechat:0.8.2:-:*:*:*:*:*:*
librechat
librechat
>>librechat>>0.8.2
cpe:2.3:a:librechat:librechat:0.8.2:rc1:*:*:*:*:*:*
librechat
librechat
>>librechat>>0.8.2
cpe:2.3:a:librechat:librechat:0.8.2:rc2:*:*:*:*:*:*
librechat
librechat
>>librechat>>0.8.2
cpe:2.3:a:librechat:librechat:0.8.2:rc3:*:*:*:*:*:*
Weaknesses
CWE IDTypeSource
CWE-306Primarysecurity-advisories@github.com
CWE ID: CWE-306
Type: Primary
Source: security-advisories@github.com
Evaluator Description

Evaluator Impact

Evaluator Solution

Vendor Statements

References
HyperlinkSourceResource
https://github.com/danny-avila/LibreChat/security/advisories/GHSA-vf7j-7mrx-hp7gsecurity-advisories@github.com
Exploit
Vendor Advisory
Hyperlink: https://github.com/danny-avila/LibreChat/security/advisories/GHSA-vf7j-7mrx-hp7g
Source: security-advisories@github.com
Resource:
Exploit
Vendor Advisory

Change History

0
Information is not available yet

Similar CVEs

2Records found

CVE-2026-54040
Matching Score-6
Assigner-GitHub, Inc.
ShareView Details
Matching Score-6
Assigner-GitHub, Inc.
CVSS Score-5.9||MEDIUM
EPSS-0.15% / 4.60%
||
7 Day CHG~0.00%
Published-25 Jun, 2026 | 15:45
Updated-29 Jun, 2026 | 16:00
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
LibreChat: 2FA Backup Code Regeneration Without OTP Verification Allows 2FA Bypass

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, the POST /api/auth/2fa/backup/regenerate endpoint regenerates all 2FA backup codes without requiring any TOTP token or existing backup code verification. An attacker with a stolen session token can silently replace a victim's backup codes and use them to bypass 2FA login or disable 2FA entirely. This vulnerability is fixed in 0.8.4-rc1.

Action-Not Available
Vendor-librechatdanny-avila
Product-librechatLibreChat
CWE ID-CWE-306
Missing Authentication for Critical Function
CVE-2026-54036
Matching Score-6
Assigner-GitHub, Inc.
ShareView Details
Matching Score-6
Assigner-GitHub, Inc.
CVSS Score-5.3||MEDIUM
EPSS-0.21% / 11.57%
||
7 Day CHG~0.00%
Published-25 Jun, 2026 | 15:39
Updated-26 Jun, 2026 | 19:02
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
LibreChat: 2FA Re-enrollment Allows Full Account 2FA Takeover Without OTP Verification

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, the GET /api/auth/2fa/enable endpoint can be called by an authenticated user (or attacker with a stolen session) even when 2FA is already fully enabled on the account. This endpoint overwrites the existing TOTP secret, generates new backup codes, and sets twoFactorEnabled to false — all without requiring any TOTP or backup code verification. An attacker with a valid session token can completely take over a victim's 2FA, locking the legitimate user out of their own two-factor authentication. This vulnerability is fixed in 0.8.4-rc1.

Action-Not Available
Vendor-librechatdanny-avila
Product-librechatLibreChat
CWE ID-CWE-306
Missing Authentication for Critical Function
Details not found