known ransomware use

PaperCut NG/MF Improper Authentication Vulnerability

Added to KEV
2026-04-20
Federal due date
2026-05-04
Vendor
PaperCut
Product
NG/MF
EPSS
99.3th percentile (score 0.833, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2023-27351

CISA short description

PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class.

Required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

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.