CVE-2022-26485

Mozilla Firefox Use-After-Free Vulnerability

High 8.8
Exploited: added to CISA KEV 7 Mar 2022

Description

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.

Key facts

Published: 22 Dec 2022
Last changed: 21 Oct 2025
Assigned by: mozilla
KEV added: 7 Mar 2022
KEV fix due: 21 Mar 2022
EPSS: 14.261% likely to be exploited in the next 30 days, higher than 96.652% of CVEs (scores for 15 Nov 2026)
SSVC (CISA): Exploitation: active; Automatable: no; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

8.8CVSS 3.1, Highfrom CISA (ADP container)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

What to do

Apply updates per vendor instructions.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Vendor	Product	Versions
Mozilla	Firefox	unspecified up to but excluding 97.0.2 (affected)
Mozilla	Firefox ESR	unspecified up to but excluding 91.6.1 (affected)
Mozilla	Firefox for Android	unspecified up to but excluding 97.3.0 (affected)
Mozilla	Thunderbird	unspecified up to but excluding 91.6.2 (affected)
Mozilla	Focus	unspecified up to but excluding 97.3.0 (affected)