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U.S. CISA adds Red Hat, Linux Kernel, Ajax.NET Professional, Microsoft SQL Server, and Citrix NetScaler flaws to its Known Exploited Vulnerabilities catalog

CISA added six flaws, including actively exploited CVE-2026-8452 in Citrix NetScaler, to its Known Exploited Vulnerabilities catalog with federal patch deadlines.

CISA added six vulnerabilities to its KEV catalog: CVE-2015-3246 and CVE-2015-5287 (Red Hat libuser race condition and ABRT privilege escalation), CVE-2019-1068 (Microsoft SQL Server RCE), CVE-2021-23758 (Ajax.NET Professional deserialization), CVE-2022-0995 (Linux Kernel out-of-bounds write) and CVE-2026-8452 (Citrix NetScaler ADC/Gateway memory buffer flaw). CVE-2026-8452 has been observed under active exploitation in the wild and can cause denial-of-service. Under BOD 22-01, federal civilian agencies must patch CVE-2019-1068 and CVE-2026-8452 by August 29, 2026, and the rest by September 9, 2026.

Security Affairs · 19d agoExploit / PoC in the wildCVE-2015-3246CVE-2015-5287CVE-2019-1068+3 CVEs

AL26-019 - Vulnerabilities impacting Citrix NetScaler ADC and NetScaler Gateway - CVE-2026-19490 and CVE-2026-19489

Canadian Cyber Centre alerts on Citrix NetScaler ADC/Gateway flaws CVE-2026-19490 (authentication bypass) and CVE-2026-19489 (buffer overflow), urging emergency patching.

The Canadian Centre for Cyber Security issued alert AL26-019 covering two Citrix NetScaler vulnerabilities disclosed in a vendor advisory on August 19, 2026. CVE-2026-19490 (CWE-288) allows a remote unauthenticated attacker to bypass authentication on appliances configured as a Gateway for SSL VPN, ICA Proxy, CVPN, RDP Proxy, or as an AAA virtual server. CVE-2026-19489 (CWE-120) is a classic buffer overflow that may cause memory overflow, unpredictable behavior, or denial-of-service conditions. Affected appliances are vulnerable when configured as a SAML IdP; fixed versions include 14.1-73.32, 13.1-63.21, and 13.1-37.277 for FIPS.

Previously patched Citrix NetScaler flaw exploited in the wild (CVE-2026-8452)

Actively exploited Citrix NetScaler flaw CVE-2026-8452, patched in June, now added to CISA KEV; attackers deploy web shells and run discovery commands.

CISA added CVE-2026-8452, a memory overflow vulnerability in Citrix NetScaler ADC/Gateway, to its Known Exploited Vulnerabilities catalog on August 26, 2026, giving federal agencies until August 29 to remediate. Citrix disclosed and patched the flaw on June 30, 2026 in versions 14.1-72.61, 13.1-63.18, and 13.1-37.272. watchTowr Labs found the flaw can be chained into unauthenticated remote code execution and released a PoC on August 14. Previdian and Defused reported exploitation with web shells named x.php and z.php from at least three unique source IPs.

Help Net Security · 20d agoExploit / PoC in the wildCVE-2026-8452CVE-2015-3246CVE-2015-5287+3 CVEs

Week in review: Compromised Zimbra servers, previously patched Citrix NetScaler flaw exploited

Help Net Security's weekly digest highlights 274 compromised Zimbra servers, Gitea and Citrix NetScaler KEV additions, a PaperCut zero-day, and a suspected Iran-linked power plant attack.

The roundup reports at least 274 internet-facing Zimbra instances compromised via CVE-2026-73570, critical Gitea CVE-2026-60004 added to CISA's KEV catalog after exploitation began, and previously patched Citrix NetScaler flaw CVE-2026-8452 exploited in the wild. It also covers PaperCut NG/MF zero-day attacks, a suspected Iran-linked shutdown of a UK power plant, an FBI seizure of domains tied to a China-linked group that hit NASA, DOJ and the Senate, a cyberattack disrupting Boston Scientific, and the Manchester Airports Group breach. Additional items include Chameleon SEO poisoning phishing, Android car head unit proxy botnet malware, ReliaQuest social engineering by ShinyHunters, fake OpenAI Codex macOS malware, and AI-related workforce and supply chain interviews.

CVE-2026-19490: Critical Vulnerability Affecting Citrix NetScaler ADC and NetScaler Gateway

CVE-2026-19490 is a critical unauthenticated authentication bypass in Citrix NetScaler ADC and Gateway, remotely exploitable without user interaction.

An advisory published August 19, 2026 describes CVE-2026-19490, a critical authentication bypass affecting Citrix NetScaler ADC and NetScaler Gateway. The flaw carries a CVSS v4.0 base score of 9.3 and is remotely exploitable by unauthenticated attackers over the network without user interaction or elevated privileges. NetScaler ADC and Gateway are widely deployed enterprise products positioned at or near the network perimeter, providing load balancing, SSL/TLS offloading, and secure remote access. The text does not state whether exploitation has been observed in the wild.

Rapid7 Blog · 27d agoVulnerabilityCVE-2026-194901

You’re Back In The Room (Citrix NetScaler Pre-Auth RCE CVE-2026-8452(?))

watchTowr Labs details a pre-authentication remote code execution flaw, tracked as CVE-2026-8452, in Citrix NetScaler appliances.

watchTowr Labs published technical analysis of a pre-authentication remote code execution vulnerability in Citrix NetScaler, tentatively assigned CVE-2026-8452. The CVE identifier is marked as provisional in the write-up. No confirmation of in-the-wild exploitation is provided in the available text.

watchTowr Labs · Aug 14, 2026Exploit / PoCCVE-2026-8452