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

> Attackers with configuration access can execute arbitrary Java bytecode via unsafe dynamic class loading in PaperCut MF/NG database connectors.

- **Severity:** Critical 9.4 (`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`)
- **Exploited in the wild:** Yes, since 31 Aug 2026 (CISA KEV)
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Aug 2026
- **Updated:** 13 Sep 2026
- **Also known as:** GHSA-mjg5-wj9r-9mfx

## What is CVE-2026-82078?

CVE-2026-82078 is a critical code injection vulnerability in PaperCut MF/NG, published on 28 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official 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.

Weakness: CWE-470 (Use of Externally-Controlled Input to Select Classes or Code)

## Which versions are affected by CVE-2026-82078?

It affects 2 products.


Products: Papercut Papercut Mf, Papercut Papercut Ng.

## How do I fix CVE-2026-82078?

No fix has been published for CVE-2026-82078 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 14 Sep 2026.

## Is CVE-2026-82078 being exploited?

Yes. Attackers have exploited CVE-2026-82078 in the wild since at least 31 Aug 2026.

Public exploit code:

- PaperCut NG/MF Unauthenticated RCE (CVE-2026-81578 + CVE-2026-82078) (metasploit)

## Other vulnerabilities in PaperCut MF/NG

- [CVE-2023-27350](https://insights.sbomify.com/CVE-2023-27350/): PaperCut MF/NG Improper Access Control (critical 9.8, exploited in the wild)
- [CVE-2026-81578](https://insights.sbomify.com/CVE-2026-81578/): PaperCut NG/MF Missing Authentication for Critical Function (high 8.8, exploited in the wild)
- [CVE-2023-2533](https://insights.sbomify.com/CVE-2023-2533/): PaperCut NG/MF Cross-Site Request Forgery (CSRF) (high 8.4, exploited in the wild)
- [CVE-2023-27351](https://insights.sbomify.com/CVE-2023-27351/): PaperCut NG/MF Improper Authentication (high 8.2, exploited in the wild)
- [CVE-2023-39143](https://insights.sbomify.com/CVE-2023-39143/): Path traversal in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82078 and fix it if it is affected.

What it is: CVE-2026-82078 is a critical code injection vulnerability in PaperCut MF/NG, published on 28 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-82078 in the wild since at least 31 Aug 2026.

Affected product: PaperCut MF/NG. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82078/ (Markdown: https://insights.sbomify.com/CVE-2026-82078/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82078
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82078
- OSV: https://osv.dev/vulnerability/CVE-2026-82078

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82078/
Summaries are generated and may contain mistakes; the official description above is the record.