CVE-2026-82078: PaperCut NG/MF Unsafe Reflection Vulnerability

Critical severity, CVSS 9.1. Actively exploited: in CISA KEV since 2026-08-31. EPSS: 63.5% chance of exploitation in the next 30 days.

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.

Affected products

• PaperCut PaperCut MF: before 24.1.9 (fixed in 24.1.9); from 25.0.2, before 25.0.12 (fixed in 25.0.12); from 26.0.2, before 26.0.4 (fixed in 26.0.4)
• PaperCut PaperCut NG: before 24.1.9 (fixed in 24.1.9); from 25.0.2, before 25.0.12 (fixed in 25.0.12); from 26.0.2, before 26.0.4 (fixed in 26.0.4)

Published 2026-08-28. Last modified 2026-09-14.