All vulnerabilities
CVE-2026-81578

PaperCut NG/MF Missing Authentication for Critical Function Vulnerability

PaperCut NG/MF
Open in ThreatlineRecord JSON
CVSS
8.8High
ExploitationExploited in the wildAdded to KEV 31 Aug 2026CISA KEV
Exploit odds (EPSS)85.6%Chance of exploitation activity in the next 30 days, higher than 99% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in24.1.10Also 25.0.13, 26.0.5CVE List
Federal deadline14 Sep 2026Remediation due date for US federal agenciesCISA KEV
CISA required actionApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. CISA KEV

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 27 Aug 2026Exploit code publicMetasploit
  2. 28 Aug 2026, 11:39 UTCPublishedCVE List
  3. 31 Aug 2026Added to CISA KEVCISA KEV
  4. 9 Oct 2026, 17:31 UTCFirst reported exploitedwatchTowr Labs

Public exploit code and templates 2

  • Exploit modulePaperCut NG/MF Unauthenticated RCE (CVE-2026-81578 + CVE-2026-82078) 27 Aug 2026Metasploit
  • Scanner templatePaperCut NG/MF <=26.0.4 - Unauthenticated ConfigEditor Access via Tapestry Complex-DirectNuclei

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

Description

PaperCut NG/MF contains a missing authentication for critical function vulnerability which allows an unauthenticated remote attacker to modify certain system configurations. This vulnerability can be chained with CVE-2026-82078.

Text from CVE List

Affected versions 3

  • PaperCut MF/NGaffected: all versions before 24.1.10CVE List
  • PaperCut MF/NGaffected: 25.0.0 before 25.0.13CVE List
  • PaperCut MF/NGaffected: 26.0.0 before 26.0.5CVE List

References 4