CVE-2023-27351
PaperCut NG/MF Improper Authentication Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA notes
https://www.papercut.com/kb/Main/PO-1216-and-PO-1219 ; https://nvd.nist.gov/vuln/detail/CVE-2023-27351
Description
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.
Severity
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:NExploitation Context
as of October 14, 2026- CISA added CVE-2023-27351 to the KEV catalog 1,096 days after its CVE record was published. The median for entries added in 2026 so far is 15 days.
- It is one of 5 PaperCut entries in the CISA KEV catalog, and one of 3 added in 2026.
- Its current EPSS score (78.1%) is higher than that of 62% of CISA KEV entries.
Affected Products
| Vendor | Product | Affected versions |
|---|---|---|
| PaperCut | PaperCut NG | 22.0.5 (Build 63914) |
References
2 LinksRecord Details
More from PaperCut
PaperCut MF/NG: Authentication Bypass
PaperCut MF/NG: Unsafe Dynamic Class Loading in Database Connector
PaperCut MF/NG 22.0.10 (Build 65996 2023-03-27) - Remote code execution via CSRF
PaperCut MF/NG Improper Access Control Vulnerability
Related
Tool categories
CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.