How severe is CVE-2025-66451?

CVE-2025-66451 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2025-66451 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66451?

CVE-2025-66451 affects Librechat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-66451?

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

Does CVE-2025-66451 have an EU (EUVD) identifier?

Yes. CVE-2025-66451 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-202929.

When was CVE-2025-66451 published?

CVE-2025-66451 was published on 2025-12-11 and last updated on 2026-06-17.

CVE-2025-66451

CVE-2025-66451 is a medium-severity vulnerability in Librechat with a CVSS 3.x base score of 6.5. 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 5.3
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-202929
Weakness: CWE-20
Affected product: Librechat
Published: 2025-12-11
Last modified: 2026-06-17

Description

LibreChat is a ChatGPT clone with additional features. In versions 0.8.0 and below, when creating prompts, JSON requests are sent to define and modify the prompts via PATCH endpoint for prompt groups (/api/prompts/groups/:groupId). However, the request bodies are not sufficiently validated for proper input, enabling users to modify prompts in a way that was not intended as part of the front end system. The patchPromptGroup function passes req.body directly to updatePromptGroup() without filtering sensitive fields. This issue is fixed in version 0.8.1.

Frequently asked questions

What is CVE-2025-66451?: LibreChat is a ChatGPT clone with additional features. In versions 0.8.0 and below, when creating prompts, JSON requests are sent to define and modify the prompts via PATCH endpoint for prompt groups (/api/prompts/groups/:groupId). However, the request bodies are not sufficiently validated for proper input, enabling users to modify prompts in a way that was not intended as part of the front end system. The patchPromptGroup function passes req.body directly to updatePromptGroup() without filtering sensitive fields. This issue is fixed in version 0.8.1.
How severe is CVE-2025-66451?: CVE-2025-66451 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2025-66451 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66451?: CVE-2025-66451 affects Librechat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66451?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-66451 have an EU (EUVD) identifier?: Yes. CVE-2025-66451 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-202929.
When was CVE-2025-66451 published?: CVE-2025-66451 was published on 2025-12-11 and last updated on 2026-06-17.

References

Affected products (1)

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

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