Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer
What to do
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 deadline 2026-10-07 · due tomorrow · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
Citrix NetScaler ADC (formerly Citrix ADC) and Citrix NetScaler Gateway (formerly Citrix Gateway) contain an improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for a denial of service.
Who is affected
Citrix NetScaler. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-119.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinedue tomorrow
Sources
- NVD entry for CVE-2026-88779 nvd.nist.gov/vuln/detail/CVE-2026-88779
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- support.citrix.com support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697174
- community.citrix.com community.citrix.com/techzone-blogs/110_security-updates/understanding-and-addressing-cve-2026-88779-in-citrix-netscaler-adc-and-citrix-netscaler-gateway/
- cisa.gov www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- cisa.gov www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2026-88779