CVE-2023-27351VulnerabilityPublished 04/20/2026Updated 10/24/2026
CVE-2023-27351: PaperCut NG/MF Improper Authentication Vulnerability
Affects PaperCut NG/MFSource CISA KEV
Severity
HighNo CVSS score published yet
- Exploitation
Actively exploited – in CISA KEV since 04/20/2026
- KEV deadline
- 05/04/2026
- Ransomware
- Used in ransomware campaigns
- EPSS
- 78.1% chance of exploitation in 30 days – higher than 99% of CVEs
What to do
CISA 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.
Description
PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class.