Exploitation evidence
Known exploited · CISA KEV listed
Added 2026-09-27. Ransomware campaign use: Unknown.
CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA due date: 2026-09-30. 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
Citrix NetScaler / ADC
Default status: unaffected
- affected: 0 to < 14.1-73.37 (patch)
- affected: 0 to < 13.1-64.23 (patch)
- affected: 0 to < 14.1-73.37 FIPS (patch)
- affected: 0 to < 13.1.37.279 FIPS and NDcPP (patch)
Citrix NetScaler / Gateway
Default status: unaffected
- affected: 0 to < 14.1-73.37 (patch)
- affected: 0 to < 13.1-64.23 (patch)
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
CVE Program record ↗ · Download tracked evidence as JSON
- https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-88771
Monitored source mentions
Shared CVE identifiers link source mentions; they do not establish that the reports describe the same incident.
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": 0.81894,
"percentile": 0.99656
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.81894,
"percentile": 0.99654
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.81894,
"percentile": 0.99653
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.81894,
"percentile": 0.99653
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.81894,
"percentile": 0.99652
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.81894,
"percentile": 0.99653
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.81894,
"percentile": 0.99652
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.83203,
"percentile": 0.99679
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.8216,
"percentile": 0.99656
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.8216,
"percentile": 0.99655
}03 Nov 2026, 02:22 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-88771",
"options": [
{
"Exploitation": "active"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-27T00:00:00+00:00",
"version": "2.0.3"
},
"type": "ssvc"
}
},
{
"other": {
"content": {
"dateAdded": "2026-09-27",
"reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-88771"
},
"type": "kev"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-09-29T03:55:15.090Z",
"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-2026-88771"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "ADC",
"vendor": "Citrix NetScaler",
"versions": [
{
"lessThan": "14.1-73.37",
"status": "affected",
"version": "0",
"versionType": "patch"
},
{
"lessThan": "13.1-64.23",
"status": "affected",
"version": "0",
"versionType": "patch"
},
{
"lessThan": "14.1-73.37 FIPS",
"status": "affected",
"version": "0",
"versionType": "patch"
},
{
"lessThan": "13.1.37.279 FIPS and NDcPP",
"status": "affected",
"version": "0",
"versionType": "patch"
}
]
},
{
"defaultStatus": "unaffected",
"product": "Gateway",
"vendor": "Citrix NetScaler",
"versions": [
{
"lessThan": "14.1-73.37",
"status": "affected",
"version": "0",
"versionType": "patch"
},
{
"lessThan": "13.1-64.23",
"status": "affected",
"version": "0",
"versionType": "patch"
}
]
}
],
"datePublic": "2026-09-27T15:51:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.<p>This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23 leading to <span>an unauthenticated attacker to execute arbitrary commands. </span></p>"
}
],
"value": "Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.\n\nThis issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23 leading to an unauthenticated attacker to execute arbitrary commands."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 9.5,
"baseSeverity": "CRITICAL",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "HIGH",
"subIntegrityImpact": "HIGH",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "CWE-20 Improper input validation",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-27T16:02:07.001Z",
"orgId": "50a63c94-1ea7-4568-8c11-eb79e7c5a2b5",
"shortName": "NetScaler"
},
"references": [
{
"url": "https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096"
}
],
"source": {
"discovery": "UNKNOWN"
},
"title": "A remote code execution vulnerability exists due to improper input validation, which can allow an unauthenticated attacker to execute arbitrary commands",
"x_generator": {
"engine": "Vulnogram 1.0.4"
}
}
},
"cveMetadata": {
"assignerOrgId": "50a63c94-1ea7-4568-8c11-eb79e7c5a2b5",
"assignerShortName": "NetScaler",
"cveId": "CVE-2026-88771",
"datePublished": "2026-09-27T16:02:07.001Z",
"dateReserved": "2026-09-10T07:14:57.369Z",
"dateUpdated": "2026-09-29T03:55:15.090Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2026-88771",
"cwes": [
"CWE-119"
],
"dateAdded": "2026-09-27",
"dueDate": "2026-09-30",
"forensicTriage": "Yes",
"knownRansomwareCampaignUse": "Unknown",
"notes": "Running the provided IOCs in the NetScaler console may help identify indicators of exploitation. Customers must conduct forensic triage as directed by BOD 26‑04 and follow Citrix’s published guidance for mitigations. For more information, please see: https://community.citrix.com/techzone-blogs/110_security-updates/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve-2026-88771-through-cve-2026-88778 ; https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096 ; https://support.citrix.com/external/article/CTX694799/steps-to-take-if-netscaler-adc-is-suspec.html ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-88772",
"product": "NetScaler",
"requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
"shortDescription": "Citrix NetScaler ADC and NetScaler Gateway contain an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.",
"vendorProject": "Citrix",
"vulnerabilityName": "Citrix NetScaler Improper Input Validation Vulnerability"
}