Is CVE-2026-4276 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-4276 being exploited in the wild.

How severe is CVE-2026-4276?

High severity, with a CVSS score of 7.5, published 16 March 2026.

Is there a fix for CVE-2026-4276?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-4276 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-4276?

Check whether you run LibreChat or LibreChat RAG API at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-4276: LibreChat RAG API log injection in file_id parameter

CVE-2026-4276 · Severity: high · CVSS 7.5 · Published 2026-03-16

LibreChat RAG API, a service used to process and search through uploaded documents using AI, contains a flaw that allows users to inject fake entries into system logs. This could allow a malicious actor to hide their activities, frame other users, or disrupt digital forensics during an investigation. If these logs are viewed through certain management tools, it could also lead to further technical attacks on administrative systems.

Technologies: LibreChat. Vendors: LibreChat.

Quick answers

Is CVE-2026-4276 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-4276 being exploited in the wild.
How severe is CVE-2026-4276?: High severity, with a CVSS score of 7.5, published 16 March 2026.
Which products and versions are affected?: LibreChat RAG API 0.7.0.
Is there a fix for CVE-2026-4276?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-4276 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-4276?: Check whether you run LibreChat or LibreChat RAG API at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A log-injection vulnerability exists in the LibreChat RAG API (version 0.7.0) due to improper sanitization of user-supplied input before it is written to system logs. Specifically, an attacker can insert Carriage Return and Line Feed (CRLF) characters into the 'file_id' parameter of a POST request to the FastAPI-based backend. This allows for the creation of forged log entries, which can be used to obfuscate malicious activity or misdirect forensic investigations. While the CVSS vector provided by CISA-ADP suggests no authentication is required (PR:N), the advisory text mentions 'authenticated attackers' in the impact description. As of the disclosure date, no official patch is available; mitigations include implementing input sanitization filters and validating RAG output before it is processed by downstream log-management tools.

Affected products

LibreChat LibreChat RAG API 0.7.0

Timeline

2026-01-26: other: Vendor notified
2026-03-16: disclosed: Public disclosure by CERT/CC
2026-03-16: advisory: NVD publication date

References

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