CVE-2025-6543

CRITICALNVD 9.89.8—Trending — 4 sources updated this weekExploited in the wild

9.8

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

CVSS v3: 9.8
EG Score: 9.8(high)
EPSS: 78.1%
KEV: ⚠ Exploited

Published

June 25, 2025

Last Modified

October 24, 2025

Advisory Details (2)

Auto-updated May 31, 2026

⚠️ Active exploitation confirmed. Patch available. Sources: cisa.

cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-6543

generic

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https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX694788

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-119Buffer Operations Within Bounds (Buffer Overflow)

Data Freshness Timeline

(refreshed 20× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-07 12:09 UTCEG score recompute
2026-06-07 12:09 UTCGHSA enrichment
2026-06-07 08:08 UTCEG score recompute
2026-06-07 08:08 UTCGHSA enrichment
2026-06-07 04:07 UTCEG score recompute
2026-06-07 04:07 UTCGHSA enrichment
2026-06-07 00:06 UTCEG score recompute
2026-06-07 00:06 UTCGHSA enrichment
2026-06-06 20:05 UTCEG score recompute
2026-06-06 20:05 UTCGHSA enrichment
2026-06-06 16:04 UTCEG score recompute
2026-06-06 16:04 UTCGHSA enrichment
2026-06-06 13:47 UTCepss_batch
2026-06-06 13:47 UTCepss_batch
2026-06-06 12:02 UTCEG score recompute
2026-06-06 12:02 UTCGHSA enrichment
2026-06-06 08:02 UTCEG score recompute
2026-06-06 08:02 UTCGHSA enrichment
2026-06-06 04:01 UTCEG score recompute
2026-06-06 04:01 UTCGHSA enrichment

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

GitHub PoCabrewer251/CVE-2025-6543_CitrixNetScaler_PoC
First seen Jul 3, 2025
Multi-host, multi-port scanner and auditor for CVE-2025-6543-affected NetScaler devices. Supports SNMP and SSH enumeration with optional CSV reporting and exploit stubs.
Open source ↗
GitHub PoCgrupooruss/Citrix-cve-2025-6543
First seen Jun 26, 2025
Script para determinar si Citrix es vulnerable al CVE-2025-6543
Open source ↗

Frequently asked(6)

What is CVE-2025-6543?

CVE-2025-6543 is a critical vulnerability published on June 25, 2025. 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

When was CVE-2025-6543 disclosed?

CVE-2025-6543 was first published in the National Vulnerability Database on June 25, 2025, with the most recent update on October 24, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2025-6543 actively exploited?

Yes. CISA added CVE-2025-6543 to the Known Exploited Vulnerabilities catalog on June 30, 2025, affecting Citrix NetScaler ADC and Gateway. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

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

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

Which products are affected by CVE-2025-6543?

CVE-2025-6543 affects Citrix NetScaler ADC and Gateway. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2025-6543?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-6543, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-6543

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CVE-2025-6543

📅 Published

🔄 Last Modified

📋 Advisory Details (2)