CVE-2026-82078
Papercut Mf ≤ 24.1.9
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-82078 is a critical-severity Unsafe Reflection (CWE-470) vulnerability in Papercut Papercut Mf. Its CVSS base score is 9.4 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Reflective Code Loading (T1620); ranked in the top 11% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-67714
Vulnerability Data
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…
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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.
- CWE(s)
- KEV Date Added
- 31 August 2026
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Input validation directly stops externally supplied class or method names from selecting improper code via reflection.
Enforces authorization checks on the code or classes ultimately invoked, blocking unauthorized selections even if reflection is used.
Limits privileges of any code reached through unsafe reflection, reducing blast radius without stopping the selection itself.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Vulnerability identification processes can discover unsafe reflection during code review or scanning.
Preventing execution of unauthorized code can block exploitation of unsafe reflection at runtime.
Secure SDLC practices directly avoid introducing externally controlled class selection via reflection.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure development lifecycle mandates input validation and design reviews that reduce unsafe reflection risks.
Application security requirements can explicitly prohibit or constrain reflection based on untrusted input.
Secure architecture principles discourage dynamic class loading from external data sources.
Secure coding standards directly forbid unsafe reflection and require whitelisting or static alternatives.
Security testing can detect and block unsafe reflection patterns before release.