PaperCut NG/MF vulnerabilities exploited in zero-day attacks
PaperCut warns of active zero-day exploitation chaining CVE-2026-81578 and CVE-2026-82078 for pre-auth remote code execution in NG/MF print management.
PaperCut Software confirmed attackers are chaining two vulnerabilities in PaperCut NG and MF: CVE-2026-81578, an improper access control flaw in the web management interface allowing unauthenticated configuration changes, and CVE-2026-82078, unsafe dynamic class loading in database connection utilities enabling arbitrary Java bytecode execution. Huntress reproduced a pre-authentication remote configuration takeover and full RCE chain against PaperCut NG 25.0.11.75758 and observed limited exploitation at two customers, including post-exploitation whoami and ver commands. The vendor released Emergency Patch Release 2 with additional hardening and urged restricting Application Server web access to trusted IPs. In 2023, Clop and LockBit affiliates abused CVE-2023-27350 and CVE-2023-27351 in the same software.
- CVE-2026-81578 allows unauthenticated config changes; CVE-2026-82078 enables bytecode execution.
- Huntress reproduced pre-auth RCE chain against stock PaperCut NG 25.0.11.75758.
- Emergency Patch Release 2 issued; install even if the first patch was applied.
- Vendor urges restricting Application Server web interfaces to trusted internal IPs.
- Clop and LockBit exploited PaperCut CVE-2023-27350/27351 in 2023.
- ATT&CK
- T1190 Exploit Public-Facing ApplicationT1033 System Owner/User DiscoveryT1082 System Information Discovery
- Products
- PaperCut NGPaperCut MF
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2023-27350 | Authentication Bypass Leading to SYSTEM RCE in PaperCut MF/NG | 9.8 | 100% | KEVRansomwarePoC ×3 | KEV |
| CVE-2023-27351 | Authentication Bypass in PaperCut NG/MF Print Management Software | 7.5 | 78% | KEVRansomware | KEV |
CVE-2026-82078+1 related CVE | Unsafe Reflection RCE in PaperCut NG/MF, Chained with Auth Bypass in Attacks | 9.4 group max | 61% | KEV | KEV |
From the original article
3 min read at helpnetsecurity.com
Two vulnerabilities (CVE-2026-82078, CVE-2026-81578) affecting print management solutions PaperCut NG and PaperCut MF are being exploited by attackers, PaperCut Software has warned. “We are aware of confirmed customer incidents and are treating this matter with the highest priority,” the vendor said . PaperCut NG is print management software for places like offices, schools, and other organizations.
By @zeljkazorz · helpnetsecurity.com
A short excerpt; the article and its images belong to the publisher. Summary, key facts and assessment above are AI-written from the article and can be wrong.