CVE-2026-54040Public exploitNetwork attack vector

2FA bypass via unverified backup-code regeneration

Published Jun 25, 2026 · Updated Jun 25, 2026

Missing authentication in LibreChat before 0.8.4-rc1 allows remote authenticated users to bypass 2FA via backup-code regeneration. The regenerateBackupCodes function overwrites stored codes and returns new plaintext codes after only requireJwtAuth, without TOTP or backup-code verification. A stolen victim session token is required; the replacement codes permit login verification or 2FA disablement, but no availability impact is reported.

CVSS severity5.9
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in LibreChat before 0.8.4-rc1 allows remote authenticated users to bypass 2FA via backup-code regeneration. The regenerateBackupCodes function overwrites stored codes and returns new plaintext codes after only requireJwtAuth, without TOTP or backup-code verification. A stolen victim session token is required; the replacement codes permit login verification or 2FA disablement, but no availability impact is reported.

The record

CVE
CVE-2026-54040
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
Danny Avila
Product
LibreChat
Classifications
CWE-306, T1556.006
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 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=< 0.8.4-rc1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Danny Avila · LibreChatversion=< 0.8.4-rc1

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
5.9GitHubCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/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-306Missing Authentication for Critical Function
T1556.006Multi-Factor Authentication

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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