---
id: "CVE-2026-117924"
kind: "vulnerability"
aliases: ["CVE-2026-117924"]
title: "Firefox: use-after-free in XSLT component fixed in several releases"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browsers", "desktop", "firefox", "runtime"]
not_affected_if: ["already-updated"]
published_at: "2026-10-27T14:16:48+00:00"
first_seen_at: "2026-10-27T14:32:23+00:00"
updated_at: "2026-10-27T14:37:15+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117924", "first_seen_at": "2026-10-27T14:32:23+00:00"}]
---

# Firefox: use-after-free in XSLT component fixed in several releases

A use-after-free bug in the XSLT component of Firefox lets memory be reused after it is freed. The sources do not say what an attacker can do with it beyond that.

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

## How to check

- Check the installed Firefox version, for example in the About Firefox dialog or with `firefox --version`
- Compare it with the fixed releases: `159`, `115.44` ESR, and `153.6` ESR
- unknown for any other check

## Fix

- Update Firefox to `159` or later on the current channel
- Update Firefox ESR to `115.44` or `153.6` on the ESR channel
- unknown for any other action

## Timeline

- 2026-10-27T14:32:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117924

## From the sources

Use-after-free in the XSLT component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.

---

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