CVE-2026-88771 (GCVE-0-2026-88771)
Vulnerability from cvelistv5 – Published: 2026-09-27 16:02 – Updated: 2026-09-28 03:55Title
A remote code execution vulnerability exists due to improper input validation, which can allow an unauthenticated attacker to execute arbitrary commands
Summary
Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.
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 an unauthenticated attacker to execute arbitrary commands.
Severity
SSVC
Exploitation: active
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-27 00:00 UTC
CWE
- CWE-20 - Improper input validation
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://support.citrix.com/support-home/kbsearch/… | |
| https://www.cisa.gov/known-exploited-vulnerabilit… | government-resource |
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Citrix NetScaler | ADC |
Affected:
0 , < 14.1-73.37
(patch)
Affected: 0 , < 13.1-64.23 (patch) Affected: 0 , < 14.1-73.37 FIPS (patch) Affected: 0 , < 13.1.37.279 FIPS and NDcPP (patch) |
guessed | |
| Citrix NetScaler | Gateway |
Affected:
0 , < 14.1-73.37
(patch)
Affected: 0 , < 13.1-64.23 (patch) |
guessed |
Date Public
2026-09-27 15:51
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 19b155ec-5037-4ef9-8d72-56443e460a6d
Exploited: Yes
Timestamps
First Seen: 2026-09-27
Asserted: 2026-09-27
Scope
Notes: Citrix NetScaler Improper Input Validation Vulnerability | Affected: Citrix / NetScaler | Description: Citrix NetScaler ADC and NetScaler Gateway contain an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands. | 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. | Due date: 2026-09-30 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): 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
Evidence
Type: Vendor Report
Signal: Successful Exploitation
Confidence: 80%
Source: cisa-kev
Details
| Cwes | CWE-119 |
|---|---|
| Feed | CISA Known Exploited Vulnerabilities Catalog |
| Product | NetScaler |
| Due Date | 2026-09-30 |
| Date Added | 2026-09-27 |
| Vendorproject | Citrix |
| Vulnerabilityname | Citrix NetScaler Improper Input Validation Vulnerability |
| Knownransomwarecampaignuse | Unknown |
References
Created: 2026-09-27 22:00 UTC
| Updated: 2026-09-27 22:00 UTC
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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