Exploitation evidence
Known exploited · CISA KEV listed
Added 2026-04-20. Ransomware campaign use: Known.
CISA 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 due date: 2026-05-04. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
PaperCut / NG
Default status: Not specified
- affected: 22.0.5 (Build 63914)
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.78052,
"percentile": 0.99581
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.78052,
"percentile": 0.99578
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.78052,
"percentile": 0.99578
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.78052,
"percentile": 0.99578
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.78052,
"percentile": 0.99578
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.78052,
"percentile": 0.99578
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.78052,
"percentile": 0.99577
}05 Nov 2026, 00:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-02T12:09:43.371Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_transferred"
],
"url": "https://www.papercut.com/kb/Main/PO-1216-and-PO-1219"
},
{
"tags": [
"x_transferred"
],
"url": "https://www.zerodayinitiative.com/advisories/ZDI-23-232/"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2023-27351",
"options": [
{
"Exploitation": "active"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-04-21T03:55:38.095423Z",
"version": "2.0.3"
},
"type": "ssvc"
}
},
{
"other": {
"content": {
"dateAdded": "2026-04-20",
"reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27351"
},
"type": "kev"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-01T18:09:39.306Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"government-resource"
],
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27351"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "NG",
"vendor": "PaperCut",
"versions": [
{
"status": "affected",
"version": "22.0.5 (Build 63914)"
}
]
}
],
"credits": [
{
"lang": "en",
"value": "Piotr Bazydlo (@chudypb) of Trend Micro Zero Day Initiative"
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV3_0": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 8.2,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "LOW",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
"version": "3.0"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-287",
"description": "CWE-287: Improper Authentication",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2023-04-20T15:35:13.491Z",
"orgId": "99f1926a-a320-47d8-bbb5-42feb611262e",
"shortName": "zdi"
},
"references": [
{
"url": "https://www.papercut.com/kb/Main/PO-1216-and-PO-1219"
},
{
"url": "https://www.zerodayinitiative.com/advisories/ZDI-23-232/"
}
]
}
},
"cveMetadata": {
"assignerOrgId": "99f1926a-a320-47d8-bbb5-42feb611262e",
"assignerShortName": "zdi",
"cveId": "CVE-2023-27351",
"datePublished": "2023-04-20T00:00:00.000Z",
"dateReserved": "2023-02-28T00:00:00.000Z",
"dateUpdated": "2026-10-01T18:09:39.306Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.78052,
"percentile": 0.99576
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.78052,
"percentile": 0.99576
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.78052,
"percentile": 0.99575
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2023-27351",
"cwes": [
"CWE-287"
],
"dateAdded": "2026-04-20",
"dueDate": "2026-05-04",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Known",
"notes": "https://www.papercut.com/kb/Main/PO-1216-and-PO-1219 ; https://nvd.nist.gov/vuln/detail/CVE-2023-27351",
"product": "NG/MF",
"requiredAction": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.",
"shortDescription": "PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class.",
"vendorProject": "PaperCut",
"vulnerabilityName": "PaperCut NG/MF Improper Authentication Vulnerability"
}