# CVE-2026-2634: Spoofed web content presented under trusted domains using scripted navigation on Firefox iOS

> Attackers can spoof trusted domains in Firefox iOS via scripted navigation, misleading users about the current site.

- **Severity:** Critical 9.8 (`CVSS:3.1/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:** No
- **Published:** 24 Feb 2026
- **Updated:** 13 Apr 2026
- **Also known as:** GHSA-gwgg-r543-4wvw, UBUNTU-CVE-2026-2634

## What is CVE-2026-2634?

CVE-2026-2634 is a critical vulnerability in Mozilla Firefox, published on 24 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Malicious scripts could cause desynchronization between the address bar and web content before a response is received in Firefox iOS, allowing attacker-controlled pages to be presented under spoofed domains. This vulnerability was fixed in Firefox for iOS 147.4.

Weakness: CWE-451 (User Interface (UI) Misrepresentation of Critical Information)

## Which versions are affected by CVE-2026-2634?

It affects 1 product.


Products: Mozilla Firefox.

## How do I fix CVE-2026-2634?

No fix has been published for CVE-2026-2634 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2634 being exploited?

There is no known exploitation of CVE-2026-2634 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-2026-2634 and fix it if it is affected.

What it is: CVE-2026-2634 is a critical vulnerability in Mozilla Firefox, published on 24 Feb 2026. 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-2026-2634 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-2026-2634/ (Markdown: https://insights.sbomify.com/CVE-2026-2634/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2634
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2634
- OSV: https://osv.dev/vulnerability/CVE-2026-2634

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-2634/
Summaries are generated and may contain mistakes; the official description above is the record.