# CVE-2025-8848: HTML Injection in Accept-Language Header in danny-avila/librechat

> Attackers can inject arbitrary HTML via the Accept-Language header, potentially leading to cross-site scripting attacks against logged-in users.

- **Severity:** Medium 4.8 (`CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 22 Oct 2025
- **Updated:** 30 Oct 2025
- **Also known as:** GHSA-xqvm-m8v9-8w9h

## What is CVE-2025-8848?

CVE-2025-8848 is a medium-severity cross-site scripting vulnerability in Librechat Librechat, published on 22 Oct 2025. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2025-8848?

It affects 1 product.


Products: Librechat Librechat.

## How do I fix CVE-2025-8848?

No fix has been published for CVE-2025-8848 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-8848 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-8848 exists.

Public exploit code:

- LibreChat <= 0.7.9 - HTML Injection via Accept-Language Header (nuclei): http/cves/2025/CVE-2025-8848.yaml

## Other vulnerabilities in Librechat Librechat

- [CVE-2026-32625](https://insights.sbomify.com/CVE-2026-32625/): LibreChat Exfiltrates Server Secrets via MCP Server URL Injection (critical 9.6)
- [CVE-2024-11167](https://insights.sbomify.com/CVE-2024-11167/): Improper Access Control in danny-avila/librechat (critical 9.4)
- [CVE-2026-22252](https://insights.sbomify.com/CVE-2026-22252/): LibreChat MCP Stdio Remote Command Execution (critical 9.1)
- [CVE-2025-69222](https://insights.sbomify.com/CVE-2025-69222/): LibreChat is vulnerable to Server-Side Request Forgery due to missing restrictions (critical 9.1)
- [CVE-2024-41704](https://insights.sbomify.com/CVE-2024-41704/): Path traversal in n/a (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-8848 and fix it if it is affected.

What it is: CVE-2025-8848 is a medium-severity cross-site scripting vulnerability in Librechat Librechat, published on 22 Oct 2025. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-8848 exists.

Affected product: Librechat Librechat. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-8848/ (Markdown: https://insights.sbomify.com/CVE-2025-8848/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-8848
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-8848
- OSV: https://osv.dev/vulnerability/CVE-2025-8848

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-8848/
Summaries are generated and may contain mistakes; the official description above is the record.