| CVE | CVE-2026-82078 |
| Vulnerability Name | PaperCut NG/MF Unsafe Reflection Vulnerability |
| CVSS Score / Version | 9.1 (Critical) / CVSS v3.1 |
| Updated | 2026-09-20 |
| CVSS Vector | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
| CVSS Prose | attack vector is network; attack complexity is low; privileges required is high; user interaction is none; scope is changed; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | PaperCut NG/MF, PaperCut PaperCut MF, and PaperCut PaperCut NG |
| Exploitation status | Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation. |
| Classified as | CWE-470 (Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')) |
| KEV listing | Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-08-31. |
| Exploitation prediction (EPSS) | 3.84% probability of exploitation in the next 30 days (90% percentile) -- FIRST.org's EPSS model. |
| Federal remediation deadline | 2026-09-14 (CISA KEV, Binding Operational Directive). |
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.
Monitor PaperCut's web page for any future patch releases.