CVE-2023-27351
This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914). Authentication is not required to exploit this vulnerability. The specific flaw exists within the SecurityRequestFilter class. The issue results from improper implementation of the authentication algorithm. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-19226.
Actively exploited
- In the CISA exploited-vulnerabilities catalogue since Apr 20, 2026
- US federal agencies must remediate it by May 4, 2026 (BOD 22-01)
- First attack observed 7 days after disclosure
- Confirmed by sensors, not only by reports
- Used in ransomware campaigns
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Source: CISA KEV · Oct 3, 2026 Oct 2, 2026 Oct 1, 2026 Sep 30, 2026 Sep 29, 2026 Sep 27, 2026
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NAffected products
| Vendors | Product | Versions |
|---|---|---|
| papercut | papercut mf | < 20.1.7 |
| papercut | papercut ng | < 20.1.7 |
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