What is CVE-2026-3055?

CVE-2026-3055 is a critical-severity vulnerability in Citrix Netscaler Application Delivery Controller, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2026-03-23.

How severe is CVE-2026-3055?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2026-3055 known to be exploited?

Yes. CVE-2026-3055 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-30), indicating it is being actively exploited. 6 public proof-of-concept repositories are indexed.

Out-of-bounds Read in Citrix Netscaler Application Delivery Controller

CVE-2026-3055

Insufficient input validation in NetScaler ADC and NetScaler Gateway when configured as a SAML IDP leading to memory overread

Vulnerability class: Buffer Overflow

Published 2026-03-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.040 (90.5th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 90.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.872 · newest: 0.040 · change: -0.831

Affected products

Citrix Netscaler Application Delivery Controller
Citrix Netscaler Gateway
Netscaler Adc — versions 14.1, 13.1, 13.1 FIPS and NDcPP
Netscaler Gateway — versions 14.1, 13.1

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2026-03-30. 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: 2026-04-02.

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

50a63c94-1ea7-4568-8c11-eb79e7c5a2b5 (Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (Exploit, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2026-3055?: CVE-2026-3055 is a critical-severity vulnerability in Citrix Netscaler Application Delivery Controller, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2026-03-23.
How severe is CVE-2026-3055?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-3055 known to be exploited?: Yes. CVE-2026-3055 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-30), indicating it is being actively exploited. 6 public proof-of-concept repositories are indexed.