CVE-2023-27351
Improper Authentication in PaperCut NG/MF. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 20 April 2026.
- Product
- PaperCut NG/MF
- Added to CISA's catalog
- Federal fix-by date
- Ransomware
- Known to be used in ransomware
- Vendor advisories
- Sources
- CISA’s catalog, NVD entry
CISA’s description.
PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class.
More from PaperCut this year.
- CVE-2026-82078 Unsafe Reflection, added
- CVE-2026-81578 Missing Authentication for Critical Function, added
Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.