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

CISA Known Exploited Vulnerabilities

Name

PaperCut NG/MF Unsafe Reflection Vulnerability

Vendor

PaperCut

Product

NG/MF

Added to the catalog

2026-08-31

Due date for US federal agencies

2026-09-14

Weaknesses

CWE-470

Catalog version

2026.10.30

PaperCut NG/MF contains an unsafe reflection vulnerability that allows an attacker to manipulate system configuration parameters and execute arbitrary Java bytecode residing on the application classpath under the security context of the PaperCut server process. This vulnerability can be chained with CVE-2026-81578.

Required action (CISA)

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.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/?lid=2oneu2wt0ct4
• https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
• https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
• https://nvd.nist.gov/vuln/detail/CVE-2026-82078

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2026-08-28T16:18:31.240

Last modified

2026-09-14T00:16:56.777

Weaknesses

CWE-470

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.

References

• https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/ (Patch, Vendor Advisory)
• https://github.com/rapid7/metasploit-framework/pull/21842 (Issue Tracking, Patch)
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-82078 (Patch, Third Party Advisory, US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:31.494Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-82078

CVE record

Title (CNA)

PaperCut MF/NG: Unsafe Dynamic Class Loading in Database Connector

Assigner

PaperCut

State

PUBLISHED

Published

2026-08-28T11:45:25.388Z

Updated

2026-09-13T23:16:32.332Z

Problem types

CWE-470 Use of Externally-Controlled input to select classes or code ('unsafe reflection')

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.

References

• https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/

Read on 2026-11-03T02:21:15.930Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/82xxx/CVE-2026-82078.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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