CVE-2026-81578
PaperCut NG/MF Missing Authentication for Critical Function Vulnerability
Exploited in the wild
This vulnerability is on the CISA Known Exploited Vulnerabilities list, added 2026-08-31. Federal due date: 2026-09-14.
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.
Impact
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.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| PaperCut | PaperCut MF/NG | before 24.1.10 from 25.0.0 before 25.0.13 from 26.0.0 before 26.0.5 |
| Papercut | Papercut Mf | before 24.1.9 from 25.0.2 before 25.0.12 from 26.0.2 before 26.0.4 |
| Papercut | Papercut Ng | before 24.1.9 from 25.0.2 before 25.0.12 from 26.0.2 before 26.0.4 |