CVE-2026-82078 PaperCut NG/MF: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Sep 14, 2026
What to do
- Install PaperCut's security update for NG/MF. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- PaperCut NG/MF Unsafe Reflection Vulnerability
- Product
- PaperCut NG/MF
- CISA description
- 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.
- Type of flaw
- Software flaw (CWE-470)
- Confirmed exploited
- Aug 31, 2026
- US federal patch deadline
- Sep 14, 2026
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Answering about CVE-2026-82078 ·
Questions about CVE-2026-82078
Is CVE-2026-82078 being exploited?
Yes. CISA added CVE-2026-82078 to its Known Exploited Vulnerabilities catalog on Aug 31, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2026-82078?
Install PaperCut's security update for NG/MF. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2026-82078?
Only if you use PaperCut NG/MF. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.