{"id":"CVE-2026-8452","published":"2026-06-30T13:19:33Z","modified":"2026-08-27T04:18:00Z","title":"Citrix NetScaler ADC and NetScaler Gateway Improper Restriction of Operations within the Bounds of a Memory Buffer…","vendor":"Citrix","product":"NetScaler ADC and NetScaler Gateway","tier":"core","eol":null,"description":{"text":"Memory overflow vulnerability NetScaler ADC and NetScaler Gateway leading to unpredictable or erroneous behavior and Denial of Service if the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server","provenance":"source","from":"NVD"},"summary":{"text":"Citrix NetScaler ADC and NetScaler Gateway contain a memory buffer overflow flaw, classified as improper restriction of operations within the bounds of a memory buffer. It affects appliances configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or as an AAA virtual server. An attacker with network access can send crafted traffic to trigger the overflow, causing unpredictable or erroneous behaviour and denial of service, with no authentication or user interaction required. The attack only applies when the appliance is configured in one of the affected Gateway or AAA modes.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:46Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.01011,"percentile":0.63147,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2026-08-26","dueDate":"2026-08-29","ransomware":false,"requiredAction":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","notes":"https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696604 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-8452","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-08-17","exploitedFirstSeen":"2026-08-17","ransomware":false,"evidence":[{"url":"https://previdian.com/CVE-2026-8452","date":"2026-08-17"},{"url":"https://www.linkedin.com/posts/this-morning-we-started-seeing-exploitation-share-7495030099205988353-6TYd/","date":"2026-08-17"},{"url":"https://x.com/DefusedCyber/status/2089304576759415270","date":"2026-08-17"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-08-26"},{"url":"https://www.recordedfuture.com/blog/august-2026-cve-landscape","date":"2026-09-08"}],"evidenceTotal":5,"provenance":"source"},"exploited":true,"otx":{"pulseCount":44,"pulses":[{"name":"Actively_Exploited_Kev | Oct 31, 2026","url":"https://otx.alienvault.com/pulse/6ae4aefab0c2191cecd41862","created":"2026-10-30"},{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"}],"provenance":"machine"},"cwes":[{"id":"CWE-119","name":"Improper Restriction of Operations within the Bounds of a Memory Buffer"}],"references":[{"url":"https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696604","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-8452","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Remote unauthenticated attack against public-facing NetScaler appliance","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"Memory overflow vulnerability NetScaler ADC and NetScaler Gateway","start":0,"end":65}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1499.004","name":"Application or System Exploitation","tactics":["impact"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Memory overflow causes appliance denial of service","mappingType":"primary_impact","evidence":[{"from":"description","quote":"leading to unpredictable or erroneous behavior and Denial of Service","start":66,"end":134}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-40307","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-40307","exploited":true,"exploitedSince":"2026-08-26","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":5,"skipped":0,"earliest":"2023-07-20","earliestUrl":"https://github.com/securekomodo/citrixInspector","repos":[{"name":"securekomodo/citrixInspector","url":"https://github.com/securekomodo/citrixInspector","stars":96,"created":"2023-07-20"},{"name":"watchtowrlabs/watchTowr-vs-Citrix-Netscaler-PreAuth-RCE-CVE-2026-8452","url":"https://github.com/watchtowrlabs/watchTowr-vs-Citrix-Netscaler-PreAuth-RCE-CVE-2026-8452","stars":65,"created":"2026-08-14"},{"name":"BishopFox/CVE-2026-8452-check","url":"https://github.com/BishopFox/CVE-2026-8452-check","stars":1,"created":"2026-08-20"},{"name":"maxprog-svg/CitrixBleedCVE-2026-8452-2025-5777","url":"https://github.com/maxprog-svg/CitrixBleedCVE-2026-8452-2025-5777","stars":0,"created":"2026-08-30"},{"name":"techupdate24/citrix-netscaler-cve-2026-8452-rce","url":"https://github.com/techupdate24/citrix-netscaler-cve-2026-8452-rce","stars":0,"created":"2026-09-27"}]},"first":{"date":"2023-07-20","source":"PoC-in-GitHub","url":"https://github.com/securekomodo/citrixInspector"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1499.004"],"provenance":"ai"}],"timeline":[{"date":"2023-07-20","kind":"exploit-public","label":"First 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