Is CVE-2023-6549 in the CISA KEV catalog?

Yes. CVE-2023-6549 is on the CISA Known Exploited Vulnerabilities list, added 2024-01-17.

What is the CVSS severity of CVE-2023-6549?

CVE-2023-6549 has a CVSS v3 base score of 8.2 (HIGH).

What is the EPSS score for CVE-2023-6549?

CVE-2023-6549 has an EPSS score of 57.63% (99th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2023-6549

HIGHCISA KEVEPSS 99th pctl

8.2

CVSS v3

NVD

Description

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

CWE-119Buffer Overflow

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Exploit Intelligence

57.63%probability of exploitation in 30 days

99thpercentile

Very high risk: more likely to be exploited than 99% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability

Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for a denial-of-service when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Remediation due: 2024-02-07

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-26.