Auth bypass in Papercut Ng

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 SecurityRe…

Vulnerability class: Broken Authentication

EPSS: 0.833 (99.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

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.

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-27351?
CVE-2023-27351 is a high-severity vulnerability in Papercut Ng, classified under Improper Authentication. CVSS score: 8.2/10. Published 2023-04-20.
How severe is CVE-2023-27351?
High severity. CVSS v3 base score is 8.2 out of 10.
Is CVE-2023-27351 known to be exploited?
Yes. CVE-2023-27351 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-04-20), indicating it is being actively exploited. 2 public proof-of-concept repositories are indexed.