PaperCut NG/MF Improper Authentication Vulnerability

PaperCut NG/MF

PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class. Added to CISA KEV on 2026-04-20 (federal deadline 2026-05-04).

First seen: 20 Apr 2026
Last update: 20 Apr 2026, 12:00 UTC
Identifiers: CVE-2023-27351
Source: CISA KEV

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## PaperCut NG/MF Improper Authentication Vulnerability
Severity: critical, exploited in the wild. Patch status: patched.
Affected: PaperCut NG/MF
Ids: CVE-2023-27351

PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class. Added to CISA KEV on 2026-04-20 (federal deadline 2026-05-04).

## Steps
1. Search the repo, its CI and infra config for PaperCut NG/MF. If present, report the version in use and whether it's affected.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2023-27351") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://nvd.nist.gov/vuln/detail/CVE-2023-27351 https://www.papercut.com/kb/Main/PO-1216-and-PO-1219
https://pwned.coffee/i/papercut-ng-mf-improper-authentication-vulnerability-cve-2023-27351

Sources

Totalone very hot coffee