Applied Cybernetics Group
Threat intel → detection pipeline
Friday, September 18, 2026
Data as of 13:09 UTC

Mozilla Firefox Use-After-Free Vulnerability

Added to KEV
2022-03-07
Federal due date
2022-03-21
Vendor
Mozilla
Product
Firefox
EPSS
96.4th percentile (score 0.143, as of 2026-09-16)
NVD CVSS v3.1
8.8 (HIGH)
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2022-26485

CISA short description

Mozilla Firefox contains a use-after-free vulnerability in XSLT parameter processing which can be exploited to perform arbitrary code execution.

Required action

Apply updates per vendor instructions.

NVD 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.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.