CVE-2025-8848

Unknown Unknown - Not Provided

BaseFortify

Publication date: 2025-10-22

Last updated on: 2025-10-30

Assigner: huntr.dev

Description

A vulnerability in danny-avila/librechat version 0.7.9 allows for HTML injection via the Accept-Language header. When a logged-in user sends an HTTP GET request with a crafted Accept-Language header, arbitrary HTML can be injected into the <html lang=""> tag of the response. This can lead to potential security risks such as cross-site scripting (XSS) attacks.

CVSS Scores

EPSS Scores

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Meta Information

Published

2025-10-22

Last Modified

2025-10-30

Generated

2026-07-06

AI Q&A

2025-10-22

EPSS Evaluated

2026-07-05

NVD

CVE-2025-8848

Affected Vendors & Products

Vendor	Product	Version / Range
librechat	librechat	0.7.9

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-94	The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
CWE-79	The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Attack-Flow Graph

Executive Summary

This vulnerability in danny-avila/librechat version 0.7.9 allows an attacker to inject arbitrary HTML into the <html lang=""> tag of the response by sending a crafted Accept-Language HTTP header while logged in. This is an HTML injection vulnerability that can lead to cross-site scripting (XSS) attacks.

Impact Analysis

The vulnerability can allow attackers to perform cross-site scripting (XSS) attacks, which may lead to unauthorized actions on behalf of the user, theft of sensitive information, or manipulation of the web application's content.

Detection Guidance

You can detect this vulnerability by sending HTTP GET requests with crafted Accept-Language headers to the affected version of danny-avila/librechat (0.7.9) and observing if arbitrary HTML is injected into the <html lang=""> tag of the response. For example, using curl: curl -H "Accept-Language: <script>alert(1)</script>" http://target-system/ and then inspecting the response HTML for injected content. Monitoring web server logs for unusual Accept-Language header values may also help identify attempts to exploit this vulnerability.

Mitigation Strategies

Immediate mitigation steps include updating danny-avila/librechat to a version that fixes this vulnerability if available, or applying input validation and sanitization on the Accept-Language header to prevent HTML injection. Additionally, implementing Content Security Policy (CSP) headers can help mitigate the impact of potential XSS attacks. Restricting or monitoring HTTP headers for suspicious input can also reduce risk.

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