# CVE-2024-9394: Cross-site scripting in Firefox

> Attackers can execute arbitrary JavaScript via crafted multipart responses, enabling cross-origin data access on Android and limited access on desktop.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 1 Oct 2024
- **Updated:** 3 Nov 2025
- **Also known as:** DEBIAN-CVE-2024-9394, GHSA-qph8-rvxf-5936, UBUNTU-CVE-2024-9394

## What is CVE-2024-9394?

CVE-2024-9394 is a medium-severity cross-site scripting vulnerability in Mozilla Firefox, published on 1 Oct 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the `resource://devtools` origin.  This could allow them to access cross-origin JSON content. This access is limited to "same site" documents by the Site Isolation feature on desktop clients, but full cross-origin access is possible on Android versions. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Firefox ESR < 115.16, Thunderbird < 128.3, and Thunderbird < 131.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2024-9394?

It affects 3 products.


Products: Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird.

## How do I fix CVE-2024-9394?

Upgrade to a fixed version.

## Is CVE-2024-9394 being exploited?

There is no known exploitation of CVE-2024-9394 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Firefox

- [CVE-2019-11708](https://insights.sbomify.com/CVE-2019-11708/): Mozilla Firefox and Thunderbird Sandbox Escape (critical 10.0, exploited in the wild)
- [CVE-2010-3765](https://insights.sbomify.com/CVE-2010-3765/): Mozilla Multiple Products Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2022-26486](https://insights.sbomify.com/CVE-2022-26486/): Mozilla Firefox Use-After-Free (critical 9.6, exploited in the wild)
- [CVE-2022-26485](https://insights.sbomify.com/CVE-2022-26485/): Mozilla Firefox Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2019-11707](https://insights.sbomify.com/CVE-2019-11707/): Mozilla Firefox and Thunderbird Type Confusion (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-9394 and fix it if it is affected.

What it is: CVE-2024-9394 is a medium-severity cross-site scripting vulnerability in Mozilla Firefox, published on 1 Oct 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-9394 in the wild and no public exploit code.

Affected product: Mozilla Firefox. 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-2024-9394/ (Markdown: https://insights.sbomify.com/CVE-2024-9394/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-9394
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-9394
- OSV: https://osv.dev/vulnerability/CVE-2024-9394

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-9394/
Summaries are generated and may contain mistakes; the official description above is the record.