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 221 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.3 — CRITICAL
- CVSS v4.0 base score
- 9.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L - EPSS (FIRST)
- 4.0% probability of exploitation in the next 30 days, higher than 90.3% 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. Weaponised exploit code for CVE-2026-3055 is publicly available. 5 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2026/CVE-2026-3055.yaml). It currently carries a trending score of 58 in the Threadlinqs vulnerability feed.
Affected products and versions
- Citrix: Netscaler Application Delivery Controller, Netscaler Gateway
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
8 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.
- CitrixBleed 2 (CVE-2025-5777) Exploited by Anubis Ransomware Affiliates Alongside Valid VPN Credentials and RMM Tool Abuse — CRITICAL · 2026-10-27
- CVE-2026-34486: Apache Tomcat EncryptInterceptor Bypass Actively Exploited in SnowLight and AI-Assisted Campaigns — HIGH · 2026-08-05
- CitrixBleed-Class NetScaler ADC/Gateway SAML AuthnRequest Memory Disclosure (CVE-2026-8451) Exploited Within 24 Hours of Disclosure — CRITICAL · 2026-07-02
- CVE-2026-8451: Memory Overread in Citrix NetScaler ADC/Gateway SAML IdP ('CitrixBleed'-class, CVSS 8.8) — Exploited Within 24 Hours of Disclosure — HIGH · 2026-07-02
- CitrixBleed 2.0: CVE-2026-8451 NetScaler SAML IDP Memory Overread Under Active Exploitation — CRITICAL · 2026-06-30
- CitrixBleed 3 — CVE-2026-3055 & CVE-2026-4368 NetScaler ADC/Gateway Memory Overread and Session Hijack — CRITICAL · 2026-04-17
- CVE-2026-3055 & CVE-2026-4368: Citrix NetScaler ADC/Gateway Pre-Auth Memory Overread and Session Mixup — CRITICAL · 2026-03-28
- CVE-2026-3055 & CVE-2026-4368: Citrix NetScaler ADC/Gateway Unauthenticated Memory Disclosure and Session Hijacking — CRITICAL · 2026-03-24
Sources
Enriched from CVE.org, FIRST EPSS, CISA KEV, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on .