---
id: "CVE-2026-117941"
kind: "vulnerability"
aliases: ["CVE-2026-117941"]
title: "Firefox: use-after-free in CSS Object Model can be exploited"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browser", "desktop", "firefox", "runtime"]
not_affected_if: ["already-on-fixed-version"]
published_at: "2026-10-27T14:16:49+00:00"
first_seen_at: "2026-10-27T14:32:23+00:00"
updated_at: "2026-10-27T14:35:46+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117941", "first_seen_at": "2026-10-27T14:32:23+00:00"}]
---

# Firefox: use-after-free in CSS Object Model can be exploited

A use-after-free bug in the CSS Object Model component of Firefox lets memory be used after it was freed. The sources do not say what an attacker can do with it, so the impact is unconfirmed.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `firefox --version` (or check About Firefox) and compare against `159` or the ESR builds `115.44` and `153.6`
- unknown for other checks

## Fix

- Update Firefox to `159`, or Firefox ESR to `115.44` or `153.6`

## Timeline

- 2026-10-27T14:32:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117941

## From the sources

Use-after-free in the DOM: CSS Object Model component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.

---

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