known ransomware use

Adobe Flash Player Use-After-Free Vulnerability

Added to KEV
2021-11-03
Federal due date
2022-05-03
Vendor
Adobe
Product
Flash Player
EPSS
99.8th percentile (score 0.935, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2018-4878

CISA short description

Adobe Flash Player contains a use-after-free vulnerability that could allow for code execution.

Required action

The impacted product is end-of-life and should be disconnected if still in use.

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.