CVE-2026-3055 Citrix NetScaler Out-of-Bounds Read Added to KEV Catalog

CISA ICS-CERT Advisories

Published March 30th, 2026

Detected March 30th, 2026

Summary

CISA added CVE-2026-3055, a Citrix NetScaler out-of-bounds read vulnerability, to the Known Exploited Vulnerabilities (KEV) Catalog based on evidence of active exploitation. Federal Civilian Executive Branch agencies must remediate this vulnerability per Binding Operational Directive 22-01 requirements. CISA strongly urges all organizations to prioritize timely remediation as part of their vulnerability management practice.

View original document View source feed page

What changed

CISA has added CVE-2026-3055 (Citrix NetScaler Out-of-Bounds Read Vulnerability) to its Known Exploited Vulnerabilities Catalog based on evidence of active exploitation. Out-of-bounds read vulnerabilities are a frequent attack vector for malicious cyber actors and pose significant risks to enterprise networks. The vulnerability was added under criteria established by BOD 22-01, which created the KEV Catalog as a living list of CVEs carrying significant risk.

Federal Civilian Executive Branch agencies must remediate this vulnerability by the due date specified in BOD 22-01 to protect FCEB networks against active threats. Organizations should immediately identify Citrix NetScaler instances, apply vendor patches or mitigations, and prioritize this vulnerability given confirmed active exploitation in the wild. Although BOD 22-01 technically applies only to FCEB agencies, CISA strongly recommends all organizations reduce their exposure to cyberattacks by addressing KEV Catalog vulnerabilities promptly.

What to do next

Identify all Citrix NetScaler instances within your infrastructure
Apply vendor-provided patches or mitigations for CVE-2026-3055 immediately
Review BOD 22-01 remediation timelines and compliance requirements if you are a federal agency

Source document (simplified)

Alert

CISA Adds One Known Exploited Vulnerability to Catalog

Release Date

March 30, 2026

CISA has added one new vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation.

CVE-2026-3055 Citrix NetScaler Out-of-Bounds Read Vulnerability This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise.

Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the KEV Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal enterprise. BOD 22-01 requires Federal Civilian Executive Branch (FCEB) agencies to remediate identified vulnerabilities by the due date to protect FCEB networks against active threats. See the BOD 22-01 Fact Sheet for more information.

Although BOD 22-01 only applies to FCEB agencies, CISA strongly urges all organizations to reduce their exposure to cyberattacks by prioritizing timely remediation of KEV Catalog vulnerabilities as part of their vulnerability management practice. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria.

This product is provided subject to this Notification and this Privacy & Use policy.