Buffer overflow in Netscaler Adc

CVE-2025-6543

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

Vulnerability class: Buffer Overflow

EPSS: 0.011 (78.0th percentile) — read the EPSS interpretation.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

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

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-6543?
CVE-2025-6543 is a vulnerability in Netscaler Adc, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. Published 2025-06-25.
Is CVE-2025-6543 known to be exploited?
Yes. CVE-2025-6543 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-06-30), indicating it is being actively exploited. 20 public proof-of-concept repositories are indexed.