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CVE-2026-3055 Citrix CVE debrief

CVE-2026-3055 is a Citrix NetScaler out-of-bounds read vulnerability that CISA added to the Known Exploited Vulnerabilities (KEV) catalog on 2026-03-30. Because it is listed in KEV, defenders should treat it as a high-priority exposure and act on vendor guidance without delay. The supplied corpus does not include affected-version detail or a technical exploitation description beyond the vulnerability class, so response planning should center on validation, mitigation, and upgrade paths published by Citrix.

Vendor
Citrix
Product
NetScaler
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2026-03-30
Original CVE updated
2026-03-30
Advisory published
2026-03-30
Advisory updated
2026-03-30

Who should care

Organizations running Citrix NetScaler, especially teams responsible for internet-facing application delivery, VPN, or gateway services, should care immediately. Security operations, vulnerability management, and infrastructure teams should also prioritize this CVE because CISA has identified it as known to be exploited.

Technical summary

The available official data identifies CVE-2026-3055 as an out-of-bounds read issue affecting Citrix NetScaler. CISA’s KEV entry confirms active exploitation and directs organizations to apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use if mitigations are unavailable. No further technical details, affected build numbers, or exploit mechanics are provided in the supplied source corpus.

Defensive priority

Urgent. KEV inclusion means this vulnerability should be handled as a near-term remediation item, with attention to any externally exposed NetScaler deployments and any environment where Citrix’s published mitigations are not yet in place.

Recommended defensive actions

  • Review Citrix’s security bulletin referenced in the KEV entry for the specific remediation steps and any affected product guidance.
  • Apply Citrix-recommended mitigations or updates as soon as operationally possible, prioritizing internet-facing NetScaler instances.
  • If mitigations are unavailable or cannot be deployed safely, follow CISA’s guidance to discontinue use of the product until a safe remediation path exists.
  • Verify exposure across all environments, including cloud-hosted or appliance-based NetScaler deployments, and document remediation status.
  • Monitor Citrix and CISA updates for any changes to affected scope, remediation instructions, or deadlines.

Evidence notes

This debrief is based only on the supplied CISA KEV metadata and the official resource links provided in the corpus. The source identifies CVE-2026-3055 as a Citrix NetScaler out-of-bounds read vulnerability, lists it in KEV on 2026-03-30, and states a due date of 2026-04-02. The corpus also references Citrix’s security bulletin (CTX696300) through the KEV notes, but no bulletin contents were included here, so no unsupported product-version or patch specifics are asserted.

Official resources

CVE-2026-3055 was published on 2026-03-30 and added to CISA’s Known Exploited Vulnerabilities catalog the same day, with a KEV due date of 2026-04-02. This debrief is based on the supplied official metadata only.