CVE-2026-54040

Description

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.

CVSS v3.1 Score

5.9

MEDIUM

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

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.05%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-306 Missing Authentication

Affected Products

Vendor	Product	Versions
librechat	librechat	< 0.8.3

References

Advisories & Patches

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-h59w-x9h4-m6gv https://github.com/danny-avila/LibreChat/security/advisories/GHSA-h59w-x9h4-m6gv

Exploits

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-h59w-x9h4-m6gv https://github.com/danny-avila/LibreChat/security/advisories/GHSA-h59w-x9h4-m6gv

Frequently Asked Questions

What is CVE-2026-54040? +

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. It has a CVSS v3.1 base score of 5.9 (MEDIUM).

How severe is CVE-2026-54040? +

CVE-2026-54040 has a CVSS v3.1 score of 5.9 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-54040? +

CVE-2026-54040 affects products from librechat, specifically: librechat. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-54040? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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