How severe is CVE-2026-54040?

CVE-2026-54040 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.

Is CVE-2026-54040 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-54040?

CVE-2026-54040 affects Librechat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-54040?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-54040 have an EU (EUVD) identifier?

Yes. CVE-2026-54040 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39456.

When was CVE-2026-54040 published?

CVE-2026-54040 was published on 2026-06-25 and last updated on 2026-06-29.

CVE-2026-54040

CVE-2026-54040 is a medium-severity vulnerability in Librechat with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39456
Weakness: CWE-306
Affected product: Librechat
Published: 2026-06-25
Last modified: 2026-06-29

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.

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.
How severe is CVE-2026-54040?: CVE-2026-54040 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.
Is CVE-2026-54040 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-54040?: CVE-2026-54040 affects Librechat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-54040?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-54040 have an EU (EUVD) identifier?: Yes. CVE-2026-54040 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39456.
When was CVE-2026-54040 published?: CVE-2026-54040 was published on 2026-06-25 and last updated on 2026-06-29.

References

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

Affected products (1)

cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:*

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