# CVE-2020-26954: Other in Firefox

> Firefox for Android allowed malicious apps to spoof UI and perform cross-origin attacks via arbitrary manifest paths, requiring an upgrade to mitigate.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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:** 9 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-crcc-3c88-jfqc, UBUNTU-CVE-2020-26954

## What is CVE-2020-26954?

CVE-2020-26954 is a medium-severity vulnerability in Mozilla Firefox Mobile, published on 9 Dec 2020. 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

When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83.

## Which versions are affected by CVE-2020-26954?

It affects 1 product.


Products: Mozilla Firefox Mobile.

## How do I fix CVE-2020-26954?

Upgrade to a fixed version.

## Is CVE-2020-26954 being exploited?

There is no known exploitation of CVE-2020-26954 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Firefox Mobile

- [CVE-2026-84135](https://insights.sbomify.com/CVE-2026-84135/): Other issue in Firefox Focus for Android (critical 9.8)
- [CVE-2024-43111](https://insights.sbomify.com/CVE-2024-43111/): Cross-site scripting in Firefox for iOS (critical 9.8)
- [CVE-2023-49060](https://insights.sbomify.com/CVE-2023-49060/): Information disclosure in Firefox for iOS (critical 9.8)
- [CVE-2026-92033](https://insights.sbomify.com/CVE-2026-92033/): Privilege escalation in Firefox for Android (high 8.8)
- [CVE-2026-84117](https://insights.sbomify.com/CVE-2026-84117/): Privilege escalation in Firefox for Android (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26954 and fix it if it is affected.

What it is: CVE-2020-26954 is a medium-severity vulnerability in Mozilla Firefox Mobile, published on 9 Dec 2020. 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-2020-26954 in the wild and no public exploit code.

Affected product: Mozilla Firefox Mobile. 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-2020-26954/ (Markdown: https://insights.sbomify.com/CVE-2020-26954/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26954
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26954
- OSV: https://osv.dev/vulnerability/CVE-2020-26954

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26954/
Summaries are generated and may contain mistakes; the official description above is the record.