PaperCut NG/MF Unsafe Reflection Vulnerability
PaperCut — PaperCut MF/NG
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.
9.1
0.9%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
- Published
- Aug 28, 2026
- Modified
- Sep 14, 2026
- Added to KEV
- Aug 31, 2026
- Federal patch due
- Sep 14, 2026
CISA 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.
Weakness classification
Affected packages
Proof-of-concept & exploitation references
2 foundWeaponization
Public repositories whose name or description references CVE-2026-82078, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit — cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
- yora1928/PaperCut-CVE-2026-81578-82078★ 4
Security research tool for PaperCut CVE-2026-81578 & CVE-2026-82078
updated Sep 9, 2026
- virologi-info/papercut-toolkit★ 2
#PaperCut CVE-2026-81578 + CVE-2026-82078 Defense Toolkit 2 3 A **defensive** toolkit to check and understand exposure to the chained
updated Sep 5, 2026
References
Frequently asked questions
What is CVE-2026-82078?
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.
How severe is CVE-2026-82078?
CVE-2026-82078 has a CVSS base score of 9.1 out of 10 (CVSS 3.1).
Is CVE-2026-82078 actively exploited in the wild?
Yes. CVE-2026-82078 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Aug 31, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-82078?
0.9% - meaning FIRST.org's EPSS model estimates a 0.9% probability this vulnerability will be exploited in the wild within 30 days (58% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2026-82078?
We found 2 public GitHub repositories referencing CVE-2026-82078, though none matched a known Nuclei template or Metasploit module at last check. Review each one before relying on it - see the proof-of-concept section above.
What type of vulnerability is CVE-2026-82078?
CVE-2026-82078 is classified under CWE-470 (CWE-470 Use of Externally-Controlled input to select classes or code ('unsafe reflection')).
Cross-checked against
Impactr finds and proves whether CVE-2026-82078 — or flaws like it — are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.