CVE entry · CVE-2026-82078
CVE-2026-82078: PaperCut NG/MF Unsafe Reflection Vulnerability
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.
- Actively exploited: added to CISA’s KEV catalog on August 31, 2026.
- Use by ransomware: not established so far.
- Remediation deadline for US federal agencies: September 14, 2026.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes PaperCut NG/MF, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.
References
- Vendor advisory or reference cited by CISA (www.papercut.com)
- NVD entry (NIST)
- CISA KEV catalog