CVE-2026-82078
Published 2026-08-28 · Updated 2026-09-14 · Source eb41dac7-0af8-4f84-9f6d-0272772514f4
Summary
CVE-2026-82078 is a critical-severity (CVSS 9.1) vulnerability in PaperCut NG/MF. CISA added it to the Known Exploited Vulnerabilities catalog on August 31, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by September 14, 2026. CISA does not currently list it as used in ransomware campaigns. PaperCut has 5 vulnerabilities in the KEV catalog, 2 of them linked to ransomware.
All 5 known-exploited PaperCut vulnerabilities →Description
An unsafe dynamic class loading vulnerability exists in the database connection utilities of PaperCut MF and PaperCut NG. The application instantiates database driver classes based on configurable driver names without validating against an allowlist of approved drivers. If an attacker can manipulate system configuration parameters, this enables the execution of arbitrary Java bytecode residing on the application classpath under the security context of the PaperCut server process.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: PaperCut — NG/MF
Name: PaperCut NG/MF Unsafe Reflection Vulnerability
Date added: 2026-08-31 · Due: 2026-09-14
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.