CVE-2026-88771

Improper Input Validation in Citrix NetScaler. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 27 September 2026.

Product
Citrix NetScaler
Added to CISA's catalog
Federal fix-by date
Ransomware
No known use in ransomware campaigns

CISA’s description.

Citrix NetScaler ADC and NetScaler Gateway contain an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.
  • CVE-2026-88779 Improper Restriction of Operations within the Bounds of a Memory Buffer, added
  • CVE-2026-88772 Improper Restriction of Operations within the Bounds of a Memory Buffer, added
  • CVE-2026-19490 Authentication Bypass Using an Alternate Path or Channel, added
  • CVE-2026-8452 Improper Restriction of Operations within the Bounds of a Memory Buffer, added
  • CVE-2026-3055 Out-of-Bounds Read, added

Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.