CVE-2026-6180: PaperCut MF

High severity, CVSS 8.1. EPSS: 0.4% chance of exploitation in the next 30 days.

A race condition exists in PaperCut MF when processing badge-swipe data from certain HP multifunction devices. Under specific network conditions involving dropped packets and out-of-order sequence counters, the server may incorrectly process fragmented data chunks. If a sequence reset notification fails to reach the server, the server may reject the initial data chunk while erroneously accepting subsequent chunks before a connection reset completes. This leads to the registration of a truncated badge ID string. While this typically results in an authentication failure, the vulnerability is compounded in environments utilizing custom badge-ID post-processing scripts. In such configurations, the truncated string may be transformed into a valid ID belonging to a different user, leading to unauthorized session establishment (Incorrect User Login) on the device.

Affected products

• PaperCut PaperCut MF: before 24.1.9 (fixed in 24.1.9); from 25.0.2, before 25.0.10 (fixed in 25.0.10)
• PaperCut PaperCut NG: before 24.1.9 (fixed in 24.1.9); from 25.0.2, before 25.0.10 (fixed in 25.0.10)

Published 2026-05-05. Last modified 2026-06-17.