CVE-2023-27351This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914).
Updated under an hour ago ()
Does this affect you?
It affects PaperCut NG and 2 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Apr 20, 2026; federal agencies had to remediate by May 4, 2026, and it is known to be used in ransomware. Treat that date as your deadline.
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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.
- CVSS
- 8.2 HIGH (v3.0, CNA)CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
- Weakness (CWE)
- CWE-287
- Known exploited
- Added to CISA KEV Apr 20, 2026; federal remediation due May 4, 2026; known ransomware useApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- EPSS (exploitation in the next 30 days)
- 78.05% (percentile 100)
- Assigned by
- zdi
- NVD analysis
- Analyzed
- Record last updated
- Oct 1, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
PaperCut NG papercut:ng (from the name) | 22.0.5 (Build 63914) | CNA record |
papercut papercut_mf papercut:papercut_mf | from 15.0 before 20.1.7; from 21.0.0 before 21.2.11; from 22.0.0 before 22.0.9 | NVD |
papercut papercut_ng papercut:papercut_ng | from 15.0 before 20.1.7; from 21.0.0 before 21.2.11; from 22.0.0 before 22.0.9 | NVD |
References
- https://www.papercut.com/kb/Main/PO-1216-and-PO-1219vendor-advisory
- https://www.zerodayinitiative.com/advisories/ZDI-23-232/third-party-advisory, vdb-entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27351us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.