CVE-2026-81578PaperCut NG/MF Missing Authentication for Critical Function Vulnerability

BOD 26-04 remediation window

With CISA's SSVC answers for this CVE (automatable: yes, technical impact: partial), BOD 26-04 Table 1 gives 3 days on a publicly exposed asset (row 2) and 14 days on an asset that is not publicly exposed (row 10) ^S06. CISA set the catalogue due date at 14 days; under BOD 26-04 it reflects CISA's own view of whether the flaw sits on publicly exposed assets ^S07. The directive binds US federal civilian executive branch agencies only.

What CISA says

Short 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.

Required action

Apply 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.

Notes

https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-81578

CWE in the catalogue

CWE-306

Official links

• CISA KEV catalogue entry cisa.gov
• NVD record nvd.nist.gov

Vendor advisory and patch links

References NVD tags Vendor Advisory or Patch, exactly as NVD lists them.

• https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ Patch, Vendor Advisory
• https://github.com/rapid7/metasploit-framework/pull/21842 Issue Tracking, Patch
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-81578 Patch, Third Party Advisory, US Government Resource

Links in CISA's notes

• https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/
• https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
• https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
• https://nvd.nist.gov/vuln/detail/CVE-2026-81578

NVD details

CWE (NVD)

CWE-305 by eb41dac7-0af8-4f84-9f6d-0272772514f4

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS versions in NVD

V31, V40

Last modified in NVD

2026-09-14T00:16:56.207

Where each value comes from

This product uses data from the NVD API but is not endorsed or certified by the NVD. CISA does not endorse Sysprobs. Methodology.