Exploited vulnerabilities / CVE-2026-88779
Confirmed exploited · denial of service · Citrix NetScalerCVE-2026-88779
Citrix NetScaler denial of service, confirmed exploited in the wild.
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.
| CISA's name for it | Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability |
|---|---|
| Vendor and product | Citrix · NetScaler |
| Type | denial of service · CWE-119 |
| Exploited | Confirmed by CISA listed 4 October 2026 |
| Likelihood | one of the most likely to be exploited of every vulnerability tracked |
| Deadline | 7 October 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | support.citrix.com ↗ · community.citrix.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ |
Three steps, in this order
Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited.
If you cannot patch now, restrict network access to the affected product.
Check for signs of compromise since the date it was added to the list.
| CISA's 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. |
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Know before someone else finds it
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CVE-2026-88779 in short
Is CVE-2026-88779 being exploited?
Yes. CISA added CVE-2026-88779 to its Known Exploited Vulnerabilities catalogue on 4 October 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2026-88779?
US federal agencies must remediate it by 7 October 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2026-88779 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 11%, the 96th percentile of every CVE it scores.
How do I fix CVE-2026-88779?
Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited. If you cannot patch now, restrict network access to the affected product. Check for signs of compromise since the date it was added to the list.
Other Citrix vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2026-88772 | NetScaler | remote code execution | 27 September 2026 |
| CVE-2026-88771 | NetScaler | exploited vulnerability | 27 September 2026 |
| CVE-2026-19490 | NetScaler | authentication bypass | 9 September 2026 |
| CVE-2026-8452 | NetScaler ADC and NetScaler Gateway | denial of service | 26 August 2026 |
| CVE-2026-3055 | NetScaler | memory corruption | 30 March 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.