Is CVE-2025-6543 in the CISA KEV catalog?

Yes. CVE-2025-6543 is on the CISA Known Exploited Vulnerabilities list, added 2025-06-30.

What is the CVSS severity of CVE-2025-6543?

CVE-2025-6543 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2025-6543?

CVE-2025-6543 has an EPSS score of 9.76% (95th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2025-6543

CRITICALCISA KEVEPSS 95th pctl

9.8

CVSS v3

NVD

Description

Memory overflow vulnerability leading to unintended control flow and Denial of Service in NetScaler ADC and NetScaler Gateway when configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server

CWE-119Buffer Overflow

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

9.76%probability of exploitation in 30 days

95thpercentile

High risk: more likely to be exploited than 95% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Citrix NetScaler ADC and Gateway Buffer Overflow Vulnerability

Citrix NetScaler ADC and Gateway contain a buffer overflow vulnerability leading to unintended control flow and Denial of Service. NetScaler must be configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Remediation due: 2025-07-21

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 2025-10-24.