How severe is CVE-2023-6549?

CVE-2023-6549 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.

Is CVE-2023-6549 being actively exploited?

Yes. CVE-2023-6549 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-01-17, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2023-6549?

CVE-2023-6549 primarily affects Citrix Netscaler Application Delivery Controller. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-6549?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2023-6549 have an EU (EUVD) identifier?

Yes. CVE-2023-6549 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-58779. It is also flagged as exploited in the EUVD (since 2024-01-17).

When was CVE-2023-6549 published?

CVE-2023-6549 was published on 2024-01-17 and last updated on 2026-06-17.

CVE-2023-6549

CVE-2023-6549 is a high-severity vulnerability in Citrix Netscaler Application Delivery Controller with a CVSS 3.x base score of 8.2. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2024-01-17). The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 58% (99th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2024-01-17)
EU (EUVD) id: EUVD-2023-58779
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2024-01-17)
Weakness: CWE-119
Affected product: Citrix Netscaler Application Delivery Controller
Published: 2024-01-17
Last modified: 2026-06-17

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

Frequently asked questions

What is CVE-2023-6549?: 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
How severe is CVE-2023-6549?: CVE-2023-6549 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2023-6549 being actively exploited?: Yes. CVE-2023-6549 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-01-17, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2023-6549?: CVE-2023-6549 primarily affects Citrix Netscaler Application Delivery Controller. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-6549?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2023-6549 have an EU (EUVD) identifier?: Yes. CVE-2023-6549 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-58779. It is also flagged as exploited in the EUVD (since 2024-01-17).
When was CVE-2023-6549 published?: CVE-2023-6549 was published on 2024-01-17 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*
cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:*
cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*
cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*

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