# CVE-2026-8706: Sensitive user data could be leaked to other applications through Reader mode

> A malicious app on the same device could access sensitive user data by exploiting Firefox for iOS Reader mode's unauthenticated local web server.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 May 2026
- **Updated:** 19 May 2026
- **Also known as:** GHSA-4c2h-7p75-v7hg, UBUNTU-CVE-2026-8706

## What is CVE-2026-8706?

CVE-2026-8706 is a medium-severity vulnerability in Mozilla Firefox, published on 19 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Firefox for iOS hosted Reader mode on an unauthenticated local web server, allowing another application on the same device to request arbitrary URLs and receive the response rendered with the signed-in user's cookies. This vulnerability was fixed in Firefox for iOS 151.0.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-8706?

It affects 1 product.


Products: Mozilla Firefox.

## How do I fix CVE-2026-8706?

No fix has been published for CVE-2026-8706 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8706 being exploited?

There is no known exploitation of CVE-2026-8706 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-2026-8706 and fix it if it is affected.

What it is: CVE-2026-8706 is a medium-severity vulnerability in Mozilla Firefox, published on 19 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-8706 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-2026-8706/ (Markdown: https://insights.sbomify.com/CVE-2026-8706/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8706
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8706
- OSV: https://osv.dev/vulnerability/CVE-2026-8706

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8706/
Summaries are generated and may contain mistakes; the official description above is the record.