Background exploitation KEV catalog No authentication
CVE-2022-27518

Citrix Application Delivery Controller (ADC) and Gateway Authentication Bypass Vulnerability

Unauthenticated remote arbitrary code execution

CheckOps priority index
5.9/10 Patch within 7 days
Severity9.8
Probability0.7
Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 6.9% higher than 94.0% of CVEs
CVSS 3.1 9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:
Exploited for 1,421 days 13 Dec 2022
CISA due date 03 Jan 2023 for US federal agencies

Exploitation probability EPSS · FIRST

05010026 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

  • KEV catalog (CISA)13 Dec 2022
  • Exploited in EUVD (ENISA)13 Dec 2022
  • Used by ransomwareno
  • EPSS above 10 %6.9%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Affected products

Citrix Gateway, Citrix ADCApplication Delivery Controller (ADC) and Gateway
Affected versions
  • 12.1 FIPs, NDcPP
  • 13.0
  • 12.1
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-88779Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
    6.2 · Actively exploited
  • CVE-2026-88772Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
    8.5 · Actively exploited
  • CVE-2026-88771Citrix NetScaler Improper Input Validation Vulnerability
    8.7 · Actively exploited
  • CVE-2026-19490Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability
    7.1 · Actively exploited
  • CVE-2026-8452Citrix NetScaler ADC and NetScaler Gateway Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
    5.4 · Actively exploited
  • CVE-2026-3055Citrix NetScaler Out-of-Bounds Read Vulnerability
    8.9 · Background exploitation

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities