CVE-2023-27351

PaperCut NG/MF Improper Authentication Vulnerability

PaperCut NG/MF

CVSS

8.2High

ExploitationExploited in the wildAdded to KEV 20 Apr 2026. Known ransomware useCISA KEV

Exploit odds (EPSS)78.1%Chance of exploitation activity in the next 30 days, higher than 99% of CVEs. Scored 23 Oct 2026FIRST EPSS

Fixed inNone listedNo source names a fixed version. Check the vendor advisory below

Federal deadline4 May 2026Remediation due date for US federal agenciesCISA KEV

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

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Timeline

20 Apr 2023, 00:00 UTCPublishedCVE List
20 Apr 2026Added to CISA KEVCISA KEV
9 Oct 2026, 17:31 UTCFirst reported exploitedwatchTowr Labs

Public exploit code and templates 1

Scanner templatePaperCut NG - Authentication BypassNuclei

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Description

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

Text from CVE List

Affected versions 1

NGaffected: 22.0.5 (Build 63914)CVE List