Threat Intelligence / CVE / CVE-2026-3055

CVE-2026-3055 — Citrix Netscaler Application Delivery Controller

CISA KEV
CVSS v3.1 9.3 (CRITICAL) · CVSS v4.0 9.3 · EPSS 89.7% (higher than 99.5% of all scored CVEs) · Priority 9/10 · Published 2026-03-23

As of 2026-03-31, CVE-2026-3055 is a CRITICAL-severity vulnerability in Citrix Netscaler Application Delivery Controller, CVSS v3.1 9.3, EPSS 89.7% (99.5th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-30), with a US federal remediation deadline of 2026-04-02. Threadlinqs Intelligence links 6 tracked threat campaigns to CVE-2026-3055, most recently “CitrixBleed-Class NetScaler ADC/Gateway SAML AuthnRequest Memory Disclosure (CVE-2026-8451) Exploited Within 24 Hours of Disclosure”.

Last updated: 2026-03-31

What is CVE-2026-3055?

CVE-2026-3055 is a pre-authentication out-of-bounds read (CWE-125) vulnerability in Citrix NetScaler ADC and NetScaler Gateway appliances configured as SAML Identity Providers. Insufficient input validation in the SAML IDP request processing path allows unauthenticated remote attackers to craft malicious requests triggering a memory overread condition, leaking sensitive data including active session tokens, authentication state data, certificates, private keys, and user credentials from adjacent memory regions. The vulnerability requires no authentication, no user interaction, and has low attack complexity. It is the third major memory-read vulnerability in NetScaler's authentication infrastructure following CitrixBleed (CVE-2023-4966) and CitrixBleed2 (CVE-2025-5777). Over 56,000 NetScaler services are discoverable on Shodan. Patched in versions 14.1-66.59, 13.1-62.23, and 13.1-37.262.

The record classifies CVE-2026-3055 under weakness class CWE-125. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 174 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.3 — CRITICAL
CVSS v4.0 base score
9.3
EPSS (FIRST)
89.7% probability of exploitation in the next 30 days, higher than 99.5% of all scored CVEs
CISA KEV
Listed since 2026-03-30, federal remediation deadline 2026-04-02
Threadlinqs priority
9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published
2026-03-23, last modified 2026-03-31

Is CVE-2026-3055 being exploited?

CISA added CVE-2026-3055 to the Known Exploited Vulnerabilities catalog on 2026-03-30, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-04-02 under BOD 22-01. It currently carries a trending score of 45 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-3055

Vendor advisory: https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696300. Because CVE-2026-3055 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-04-02. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-3055

6 tracked threats in the Threadlinqs corpus reference CVE-2026-3055, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from threat-derived and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-3055 are available via the Threadlinqs MCP server (Purple tier). View plans →

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