Risk Letters

Exploited vulnerability

CVE-2023-27351

TLP:CLEAR

PaperCut NG/MF Improper Authentication Vulnerability

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

Facts

  • Vendor: PaperCut
  • Product: NG/MF
  • CVSS: 8.2
  • EPSS (probability of exploitation within 30 days): 78.1 %
  • On CISA's Known Exploited Vulnerabilities list since: 20 April 2026
  • First known exploitation: 20 April 2026
  • Used in ransomware campaigns (per CISA): Yes
  • CISA's deadline for US federal agencies: 4 May 2026
  • Weakness: CWE-287
  • First seen by Risk Letters: 20 April 2026

Members see which Nordic sectors the flaw hits, and what to do about it.

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD