---
id: "CVE-2022-26485"
kind: "vulnerability"
aliases: ["CVE-2022-26485"]
title: "Mozilla Firefox: Mozilla Firefox Use-After-Free Vulnerability"
severity: "high"
cvss: 8.8
epss: 0.14261
exploited: true
status: "open"
category: "package"
products: [{"name": "Mozilla Firefox", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["browser", "desktop", "exploited", "firefox", "package"]
not_affected_if: ["unknown"]
published_at: "2022-03-07T00:00:00+00:00"
first_seen_at: "2026-10-23T19:11:52+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2022-26485", "first_seen_at": "2026-10-23T19:11:52+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2022-26485", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-26485", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Mozilla Firefox: Mozilla Firefox Use-After-Free Vulnerability

Mozilla Firefox has a use-after-free bug in its XSLT parameter processing. An attacker who gets a user to load a crafted page can run arbitrary code in the browser.

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

## Affected

- vendor:Mozilla Firefox affected ? fixed ?

## How to check

Open Help > About Firefox and compare the version to the fixed release in Mozilla's advisory; unknown whether the sources list a specific version.

## Fix

Update Firefox to the latest release per Mozilla's advisory; the exact fixed version is unknown from these sources.

## Timeline

- 2026-10-23T19:11:52+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2022-26485
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2022-26485
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2022-26485

## From the sources

Removing an XSLT parameter during processing could have lead to an exploitable use-after-free. We have had reports of attacks in the wild abusing this flaw. This vulnerability affects Firefox < 97.0.2, Firefox ESR < 91.6.1, Firefox for Android < 97.3.0, Thunderbird < 91.6.2, and Focus < 97.3.0.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_