# CVE-2020-26975: Security feature bypass in Firefox

> A malicious app could inject arbitrary headers via Intents in Firefox for Android, enabling session fixation or ambient authority abuse.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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:** 7 Jan 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-cmfr-9hrr-hpg4

## What is CVE-2020-26975?

CVE-2020-26975 is a medium-severity vulnerability in Mozilla Firefox Mobile, published on 7 Jan 2021. 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 a malicious application installed on the user's device broadcast an Intent to Firefox for Android, arbitrary headers could have been specified, leading to attacks such as abusing ambient authority or session fixation. This was resolved by only allowing certain safe-listed headers. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 84.

## Which versions are affected by CVE-2020-26975?

It affects 1 product.


Products: Mozilla Firefox Mobile.

## How do I fix CVE-2020-26975?

Upgrade to a fixed version.

## Is CVE-2020-26975 being exploited?

There is no known exploitation of CVE-2020-26975 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-2020-26975 and fix it if it is affected.

What it is: CVE-2020-26975 is a medium-severity vulnerability in Mozilla Firefox Mobile, published on 7 Jan 2021. 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-2020-26975 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-2020-26975/ (Markdown: https://insights.sbomify.com/CVE-2020-26975/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26975
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26975
- OSV: https://osv.dev/vulnerability/CVE-2020-26975

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26975/
Summaries are generated and may contain mistakes; the official description above is the record.