On 2024-01-17, CISA added CVE-2023-6549 (Citrix NetScaler ADC and NetScaler Gateway) to its Known Exploited Vulnerabilities (KEV) catalog [2]. The vulnerability is listed in the catalog as "Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability" [2]. CISA requires remediation in accordance with the listed vendor mitigation guidance; see the original text in the body for specific requirements [2].
Backfill: this event became public on Jan 17, 2024 and we added it on Nov 10, 2026. It is not a new event.
CISA Adds Citrix NetScaler ADC and NetScaler Gateway Vulnerability CVE-2023-6549 to Known Exploited Vulnerabilities Catalog
1 min read
- Disclosed
- Jan 17, 2024
- Published
- Nov 10, 2026
- Last updated
- Nov 8, 2026
- CVSS basis
- Our assessment
- 57.6%, higher than 99% of CVEs
- Exploitation and patch status
- ExploitedKEV
- Attack vector
- Vulnerability status
- Actor type
- Motivation
On this page
30-second summary
What happened
Who is affected
Industries mainly affected: Government, Cross-industry
What to do nowOur advice
CISA requires remediation in accordance with the listed vendor mitigation guidance; see the original text in the body for specific requirements [2].
Timeline
Technical details
CISA KEV Listing Record
CISA added CVE-2023-6549 (Citrix NetScaler ADC and NetScaler Gateway) to the Known Exploited Vulnerabilities () catalog on 2024-01-17 [2].
Original Technical Description
Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for a denial-of-service when configured as a Gateway ( virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server. [2]
Official Required Action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. [2]
Individual Vulnerability Record
The U.S. National Vulnerability Database (NVD) provides an independent vulnerability record and description for CVE-2023-6549 [1].
References
Official / primary3
- [1]
“Improper Restriction of Operations within the Bounds of a Memory Buffer in NetScaler ADC and NetScaler Gateway allows Unauthenticated Denial of Service and Out-Of-Bounds Memory Read”
- [2]
This site aggregates public information and is not security consulting advice. Test remediation steps before applying.