---
id: "CVE-2026-118011"
kind: "vulnerability"
aliases: ["CVE-2026-118011"]
title: "Firefox: CSS parsing flaw lets a page corrupt frame memory"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browser", "desktop", "firefox", "runtime"]
not_affected_if: ["current-firefox"]
published_at: "2026-10-27T14:16:58+00:00"
first_seen_at: "2026-10-27T14:32:25+00:00"
updated_at: "2026-10-27T14:33:34+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118011", "first_seen_at": "2026-10-27T14:32:25+00:00"}]
---

# Firefox: CSS parsing flaw lets a page corrupt frame memory

A flaw in Firefox's CSS parsing and computation component allows frame poisoning, a memory corruption condition in how the browser handles style data. The sources do not state what an attacker can achieve beyond that, and the fix is in Firefox 159.

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

## How to check

- Run `firefox --version` or check Help > About Firefox and compare against `159`
- unknown

## Fix

- Update Firefox to `159` or later
- unknown

## Timeline

- 2026-10-27T14:32:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118011

## From the sources

Frame poisoning in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159.

---

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