CVE-2026-82078: PaperCut NG/MF Unsafe Reflection Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by PaperCut, published 2026-08-28).
Weakness: CWE-470 Use of Externally-Controlled input to select classes or code (‘unsafe reflection’)
How it can be exploited
Exploitable over the network with low attack complexity with no special attack requirements needing high privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. 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
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.
- On CISA KEV since
- 2026-08-31
- US federal deadline
- 2026-09-14
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: BDU:2026-15096, EUVD-2026-67714, GHSA-mjg5-wj9r-9mfx
VEDAS cluster: VEDAS:BARMYSPIRIT
Exploit Observer has no public exploit code that names this CVE or one of its aliases.
Research and write-ups (3)
- Research or write-up: https://labs.watchtowr.com/death-by-a-thousand-papercuts-papercut-pre-auth-rce-chain-and-patch-bypasses-wt-2026-0141-0144-cve-2026-82077-cve-2026-82078-cve-2026-81578
- Research or write-up: https://watchtowr.com/resources/papercut-ng-mf-zero-day-cve-2026-81578-cve-2026-82078-active-exploitation-underway
- Research or write-up: https://www.esentire.com/blog/papercut-mf-zero-day-intrusion-java-loader-web-shell-and-adaptixc2-via-cve-2026-82078-and-cve-2026-81578
Vulnerability databases and vendor advisories (5)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-67714
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-mjg5-wj9r-9mfx
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-82078
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-82078
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=cve-2026-82078
News (1)
102 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.630
very likely to be attacked soon - VEDAS
- 0.977
strong exploit evidence - On CISA KEV
- Yes, since 2026-08-31
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| PaperCut PaperCut MF/NG | before 24.1.10 from 25.0.0 before 25.0.13 from 26.0.0 before 26.0.5 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: papercut papercut_mf, papercut papercut_ng, papercut_software_international_pty_ltd papercut_mf, papercut_software_international_pty_ltd papercut_ng.
How to fix it
Fixed versions stated in the CVE record: 24.1.10, 25.0.13, 26.0.5.
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.
Vendor guidance:
- 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
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Exploits and technical analysis
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-82078 (government-resource)
Other references
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.