# SUSE-SU-2025:03447-1: Security update for MozillaFirefox

> An update to Firefox ESR resolves HTTP/3 connection stalls by improving protocol fallback reliability, preventing potential service disruptions.

- **Severity:** Not scored
- **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:** 2 Oct 2025

## What is SUSE-SU-2025:03447-1?

SUSE-SU-2025:03447-1 is a vulnerability in MozillaFirefox, published on 2 Oct 2025. 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

This update for MozillaFirefox fixes the following issues:

Update to Firefox Extended Support Release 140.3.1 ESR (bsc#1250452).

- Improved reliability when HTTP/3 connections fail: Firefox no longer forces HTTP/2 during fallback, allowing the
  server to choose the protocol and preventing stalls on some sites.

## Which versions are affected by SUSE-SU-2025:03447-1?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `MozillaFirefox` | SUSE:Linux Enterprise Server 12 SP5-LTSS | All versions | 140.3.1-112.283.1 |
| `MozillaFirefox` | SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | All versions | 140.3.1-112.283.1 |

## How do I fix SUSE-SU-2025:03447-1?

Upgrade to a fixed version.

## Is SUSE-SU-2025:03447-1 being exploited?

There is no known exploitation of SUSE-SU-2025:03447-1 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for SUSE-SU-2025:03447-1 and fix it if it is affected.

What it is: SUSE-SU-2025:03447-1 is a vulnerability in MozillaFirefox, published on 2 Oct 2025. 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 SUSE-SU-2025:03447-1 in the wild and no public exploit code.

Affected product: MozillaFirefox. 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/SUSE-SU-2025-03447-1/ (Markdown: https://insights.sbomify.com/SUSE-SU-2025-03447-1/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/SUSE-SU-2025:03447-1

---
From sbomify Insights: https://insights.sbomify.com/SUSE-SU-2025-03447-1/
Summaries are generated and may contain mistakes; the official description above is the record.