# CVE-2016-9901: Cross-site scripting in Firefox

> Attackers can inject HTML into Pocket pages to execute JavaScript and access privileged messaging APIs in Firefox.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Jun 2018
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2016-9901, GHSA-6g72-x2jp-6592, UBUNTU-CVE-2016-9901

## What is CVE-2016-9901?

CVE-2016-9901 is a critical cross-site scripting vulnerability in Mozilla Firefox, published on 11 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

HTML tags received from the Pocket server will be processed without sanitization and any JavaScript code executed will be run in the "about:pocket-saved" (unprivileged) page, giving it access to Pocket's messaging API through HTML injection. This vulnerability affects Firefox ESR < 45.6 and Firefox < 50.1.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2016-9901?

It affects 6 products.


Products: Mozilla Firefox, Redhat Enterprise Linux Aus, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Eus, Redhat Enterprise Linux Server, Redhat Enterprise Linux Workstation.

## How do I fix CVE-2016-9901?

Upgrade to a fixed version.

## Is CVE-2016-9901 being exploited?

There is no known exploitation of CVE-2016-9901 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-2016-9901 and fix it if it is affected.

What it is: CVE-2016-9901 is a critical cross-site scripting vulnerability in Mozilla Firefox, published on 11 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2016-9901 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-2016-9901/ (Markdown: https://insights.sbomify.com/CVE-2016-9901/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9901
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9901
- OSV: https://osv.dev/vulnerability/CVE-2016-9901

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-9901/
Summaries are generated and may contain mistakes; the official description above is the record.