---
id: "CVE-2026-118004"
kind: "vulnerability"
aliases: ["CVE-2026-118004"]
title: "Firefox: CSS animation boundary flaw fixed in Firefox 159 and ESR 153.6"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["desktop-browser", "firefox", "runtime"]
not_affected_if: []
published_at: "2026-10-27T14:16:58+00:00"
first_seen_at: "2026-10-27T14:32:25+00:00"
updated_at: "2026-10-27T14:33:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118004", "first_seen_at": "2026-10-27T14:32:25+00:00"}]
---

# Firefox: CSS animation boundary flaw fixed in Firefox 159 and ESR 153.6

Firefox's CSS Transitions and Animations component had an incorrect boundary condition, per the NVD entry. The sources do not say what an attacker gains from it beyond the fix being shipped in Firefox 159 and Firefox ESR 153.6.

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

## How to check

- Run `about:support` in Firefox and read the version line, then compare it with `159` or `153.6` (ESR)
- unknown

## Fix

- Update Firefox to `159` or Firefox ESR to `153.6`
- unknown

## Timeline

- 2026-10-27T14:32:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118004

## From the sources

Incorrect boundary conditions in the CSS Transitions and Animations component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.

---

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