What’s Vulnerable › Vulnerabilities
CVE-2026-82078: PaperCut NG/MF Unsafe Reflection Vulnerability
- Severity: critical (CVSS 9.1 v3.1)
- Exploited in the wild: yes — in CISA KEV since 2026-08-31
- EPSS: 63.0% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-28 · updated 2026-09-14
- Weakness: CWE-470
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.
Affected products
- PaperCut MF: before 24.1.9; from 25.0.2 before 25.0.12; from 26.0.2 before 26.0.4 — fixed in 24.1.9, 25.0.12, 26.0.4
- PaperCut NG: before 24.1.9; from 25.0.2 before 25.0.12; from 26.0.2 before 26.0.4 — fixed in 24.1.9, 25.0.12, 26.0.4
How to fix
Upgrade to a fixed version: PaperCut MF 24.1.9, 25.0.12, 26.0.4; PaperCut NG 24.1.9, 25.0.12, 26.0.4. Check the vendor advisory for mitigations.
In the news
References
- https://www.papercut.com/kb/Main/security-bulletin-27-aug-2026-urgent-security-advisory/
- https://github.com/rapid7/metasploit-framework/pull/21842
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-82078
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