PaperCut NG/MF Improper Authentication Vulnerability
PaperCut · NG/MF
CVSS 7.5
EPSS 77%
no public exploit indexed
ransomware
Fix deadline passed 4 May 2026
What it is
PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class.
Why we say that
- Linked by CISA to known ransomware campaigns
- EPSS puts exploitation in the next 30 days at 77%
- CISA's federal remediation deadline (2026-05-04) has passed
- Listed in the CISA Known Exploited Vulnerabilities catalogue
Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
What it costs when this goes wrong
This is where UK enforcement meets the vulnerability record. This vulnerability is used in ransomware campaigns; here is what ransomware has cost UK organisations at the regulator.
- Advanced Computer Software Group Limited The Information Commissioner’s Office (ICO) has fined Advanced Computer Software Group Ltd (Advanced) £3.07m for security failings…
- Optionis Group Limited The data controller suffered a ransomware attack, which resulted in the exfiltration of personal data. A reprimand was issued in r…