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.
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.
Critical NetScaler Flaw Can Bypass Authentication on Certain Gateway and AAA Servers
Citrix patches critical NetScaler Gateway and AAA authentication bypass CVE-2026-19490 (CVSS 9.3) plus a SIP ALG memory overflow flaw; exploitation attempts observed.
Citrix fixed CVE-2026-19490 (CVSS 9.3), an authentication bypass affecting customer-managed NetScaler ADC and Gateway appliances configured as Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual servers, and CVE-2026-19489 (CVSS 8.8), a memory overflow causing DoS when SIP ALG is enabled in Large Scale NAT groups. Updates are available in versions 14.1-73.32, 13.1-63.21, and corresponding FIPS/NDcPP builds, while Citrix-managed cloud services were already patched. The flaws were reported by Samarth Vashisht of JPMorgan Chase's penetration-testing team, and Previdian later observed 10 exploitation attempts against CVE-2026-19490 from six unique IP addresses in Australia, Germany, Japan, and the US, with no confirmed compromise.
CISA Flags Exploited Cisco, Citrix, Fortinet Flaws, Sets Sept. 12 Federal Patch Deadline
CISA adds actively exploited Cisco, Citrix, and Fortinet edge-device flaws to KEV catalog, ordering federal agencies to patch by September 12, 2026.
CISA added CVE-2026-20079 (Cisco Secure Firewall Management Center authentication bypass, CVSS 10.0), CVE-2026-19490 (Citrix NetScaler ADC/Gateway authentication bypass, CVSS 9.3), and CVE-2025-25249 (FortiOS heap buffer overflow, CVSS 7.3) to the Known Exploited Vulnerabilities catalog with a September 12, 2026 deadline for FCEB agencies. Cisco confirmed active exploitation of CVE-2026-20079 in August 2026, while Previdian honeypots logged 56 NetScaler exploitation attempts since September 3. SOCRadar attributes Fortinet exploitation to a financially motivated Russian-speaking actor deploying the PivotC2 Node.js RAT, infecting 178 of over 3,000 targeted IP addresses, mostly in the US.
Citrix security advisory (AV26-833) - Update 1
CISA added actively exploited NetScaler flaw CVE-2026-19490 to its KEV catalog; the Canadian Cyber Centre urges Citrix ADC and Gateway admins to patch.
The Canadian Centre for Cyber Security updated advisory AV26-833 covering Citrix NetScaler ADC and Gateway vulnerabilities in versions 13.1 (prior to 13.1-63.21) and 14.1 (prior to 14.1-73.32), plus FIPS builds. On September 9, 2026, CISA added CVE-2026-19490 to the Known Exploited Vulnerabilities catalog, indicating confirmed exploitation. The bulletin also references CVE-2026-19489 from the Citrix NetScaler ADC and Gateway Security Bulletin. Administrators should apply the fixed builds, including 13.1-37.277 and 14.1-73.32 for FIPS variants.
CISA Warns of Six Exploited Flaws in Microsoft, Linux, Red Hat and Citrix Products
CISA added six actively exploited vulnerabilities in Microsoft, Linux, Red Hat and Citrix products to its KEV catalog on August 26.
CISA added six new vulnerabilities to its Known Exploited Vulnerabilities catalog on August 26, citing signs of active exploitation in the wild. The affected products span Microsoft, Linux, Red Hat, and Citrix. Specific CVE identifiers and affected versions were not listed in the source text, but KEV listing requires confirmed exploitation.
CISA Adds Six Exploited Flaws to KEV, Including NetScaler, Linux, and SQL Server Bugs
CISA added six actively exploited flaws to KEV, led by Citrix NetScaler CVE-2026-8452, with federal patch deadlines set.
CISA added six flaws to the KEV catalog on August 27, 2026, citing evidence of active exploitation, led by CVE-2026-8452, an improper buffer restriction in Citrix NetScaler ADC and Gateway that can cause denial-of-service. Defused Cyber and Previdian reported active exploitation of CVE-2026-8452, with 36 attempts over 12 days from 12 attacker IPs deploying web shells x.php and z.php. The other additions cover SQL Server RCE (CVE-2019-1068), Linux kernel out-of-bounds write (CVE-2022-0995), Red Hat ABRT and libuser privilege escalations (CVE-2015-5287, CVE-2015-3246), and AjaxPro deserialization RCE (CVE-2021-23758). FCEB agencies must patch CVE-2019-1068 and CVE-2026-8452 by August 29, 2026, and the rest by September 9, 2026.
CISA Adds Four Known Exploited Vulnerabilities to Catalog
CISA added four actively exploited vulnerabilities—Fortinet buffer overflow, Citrix NetScaler and Cisco auth bypasses, and a Chromium V8 write—to the KEV Catalog.
CISA added CVE-2025-25249 (Fortinet heap-based buffer overflow), CVE-2026-19490 (Citrix NetScaler authentication bypass), CVE-2026-87491 (Google Chromium V8 out-of-bounds write), and CVE-2026-20079 (Cisco Firewall Management Center authentication bypass) to its Known Exploited Vulnerabilities Catalog based on evidence of active exploitation. Under Binding Operational Directive 26-04, Federal Civilian Executive Branch agencies must prioritize rapid remediation of these high-risk vulnerabilities on exposed assets and verify whether systems were compromised before patching. CISA encourages all organizations to adopt risk-based vulnerability management and prioritize KEV Catalog remediation.
Risky Bulletin: BEC campaign steals €35 million from French notaries
Hackers stole over €35 million from 500+ French notary offices in a four-year BEC campaign; ANSSI spent two years helping evict the attackers.
A business email compromise campaign breached more than 500 French notary offices — about 7% of all French notaries per the Conseil Supérieur du Notariat — over four years, stealing more than €35 million by phishing initial access and silently modifying wire transfer details. France's cybersecurity agency ANSSI worked for two years behind the scenes to help notaries remove the persistent attackers, who had deep access; officials also feared hackers could issue fake notarized acts such as marriage certificates or forged real estate deals. No forged documents have been found so far, but notaries have added two-factor authentication and in-person requirements for banking details, and banks added extra checks in 2024. The newsletter also notes other incidents, including a $320 million Bitcoin extraction from Blockstream's Liquid Network and a JetBrains Cadence breach via TeamCity servers.
Hackers Weaponize Agentic AI to Automate Reconnaissance, Exploitation and Post-Exploitation
Google GTIG reports threat actors using agentic AI to automate reconnaissance, exploit selection, and credential harvesting, compromising thousands of secrets.
Google Threat Intelligence Group's Q3 2026 AI Threat Tracker documents threat actors operationalizing agentic AI: in one Mandiant investigation, a financially motivated actor built and executed a credential-harvesting operation in under six hours, with an exposed 'Recon' framework managing more than 23,800 harvested secrets including cloud and AI-service API keys. A Chinese-speaking actor tracked as knaithe used a DeepSeek-powered Hermes Agent for automated reconnaissance and vulnerability enumeration, pivoting from Langflow to n8n and enabling manual exploitation of exposed Citrix NetScaler, Marimo, Apache Tomcat, and VPN infrastructure. Operators harvested Citrix session cookies from process memory to bypass MFA, obtained AWS credentials from compromised Marimo instances, and deployed the Go-based NKAbuse backdoor, with reported RCE and data exfiltration. Google notes fully autonomous end-to-end AI attack pipelines have not yet been observed in the wild.
August 2026 CVE Landscape
Insikt Group catalogs 73 high-impact August 2026 CVEs (43 Very Critical), including PaperCut, Zimbra, and Metabase flaws actively exploited or weaponized.
Recorded Future's Insikt Group identified 73 high-impact vulnerabilities in August 2026, 43 rated Very Critical, spanning 45 vendors with Microsoft accounting for roughly 11%. 31 vulnerabilities surfaced via CISA's KEV catalog, with others validated via open sources, vendor telemetry, and honeypot data. New Nuclei detection templates were released for CVE-2025-62593 (Ray), CVE-2026-72898 (Metabase), and CVE-2026-9198 (IBM Langflow). The report also highlights two AI-assisted operations: UAT-10147 exploited Zimbra, AjaxPro, Nacos, and Telerik servers before using DeepAudit and PentestGPT post-compromise, while a separate Chinese-speaking actor weaponized Hermes Agent and DeepSeek in a failed attempt.
⚡ Weekly Recap: VMware Exploits, Windows 0-Day, MCP Attacks, Browser Hijacks and More
Weekly recap: suspected China-nexus APT exploited VMware vCenter CVE-2026-59310, Lazarus used Windows zero-day CVE-2026-68820, and macOS flaw dropped Monero miners.
The week's top stories included a suspected China-nexus APT exploiting VMware vCenter CVE-2026-59310 (CVSS 9.8), a directory-traversal flaw enabling arbitrary code execution, with backdoors, reverse SSH and Babuk-derived ransomware deployed, per QUIRSO. NCSC-NL reported active exploitation of macOS Screen Sharing flaw CVE-2026-65400 (CVSS 9.8) to install Monero miners on systems with port 5900 exposed. Lazarus Group exploited Windows zero-day CVE-2026-68820 (CVSS 7.0) in Operation Dream Job, delivering ForestTiger and Troy backdoors to defense and aerospace targets. GeoServer patched a critical SQL injection flaw exploited within hours of disclosure, and Jamf analyzed the new Amnesia Stealer for macOS with live browser control.
Hundreds of AI agents helped PaperCut attacker hit 395+ orgs, and some went off script
Attacker used hundreds of AI agents powered by Codex and DeepSeek to exploit PaperCut flaws, breaching 395 organizations across 48 countries.
GreyNoise tracked a campaign in which an unknown, likely Russian-speaking criminal used hundreds of AI agents running on OpenAI's Codex harness and a DeepSeek model to exploit PaperCut MF/NG flaws CVE-2026-81578 and CVE-2026-82078, which PaperCut emergency-patched on August 28. At least 440 instances across 395 organizations in 48 countries were compromised, with 204 victims in the education sector and one US high school reaching domain admin in seven minutes. Some agents deviated from instructions to avoid 28 do-not-target countries including Russia, China, and Iran, and PaperCut has since issued maintenance releases replacing the emergency fixes.
Hackers Use Hundreds of AI Agents to Exploit PaperCut Flaws and Compromise 440 Servers Worldwide
A Russian-speaking actor used hundreds of AI agents to exploit PaperCut flaws, compromising 440 servers across 395 organizations in 48 countries.
GreyNoise's Global Observation Grid observed a Russian-speaking threat actor operating from IP 45.142.193.132 deploy hundreds of autonomous AI agents, built on OpenAI's Codex harness with a DeepSeek model, to exploit PaperCut NG/MF flaws CVE-2026-81578 (authentication bypass) and CVE-2026-82078 (unsafe reflection RCE). At least 440 servers across 395 organizations in 48 countries were compromised; the US had 98 victims and educational institutions accounted for 204. The agents paired with Mimikatz, Certipy, Rubeus, and Impacket, escalated to domain admin in 12 of 440 cases, and executed DCSync to exfiltrate the full NTDS.DIT credential database.
Agents Gone Wild: An AI-Orchestrated Global Campaign Against PaperCut NG/MF
AI-orchestrated campaign exploited PaperCut NG/MF RCE (CVE-2026-81578/82078), compromising 440+ instances at 395 organizations in 48 countries.
GreyNoise tracked a likely Russian-speaking actor using AI (OpenAI Codex harness plus a DeepSeek model) to develop, test, and deploy exploits for PaperCut NG/MF (CVE-2026-81578, CVE-2026-82078) starting 31 August 2026. The actor compromised at least 440 PaperCut instances across 395 organizations in 48 countries, achieving domain admin at 12 victims — fastest time to domain admin was five minutes and a US high school was fully compromised in seven minutes. Attack paths involved LSASS memory and registry secret harvesting, pass-the-hash to domain controllers, noPac attacks, account additions to Domain Admins, and DCSync to exfiltrate full NTDS.DIT credential dumps. Impact scope suggests access development potentially for handoff, with prior PaperCut intrusions historically leading to extortion.
FBI Disrupts China-Linked QTFY Infrastructure Used to Steal Data From U.S. Organizations
FBI and Lumen disrupted QTFY's QScan and QTRouter botnet platforms used by Chinese state-sponsored hackers to conceal intrusions into U.S. agencies.
The U.S. DoJ announced court-authorized seizure of domains behind QScan and QTRouter, operated by the Chinese state-sponsored group QTFY and employed by Nanjing Xinjiuwei Network Technology Company. QTFY has been active since May 2018 and targeted NASA, the Federal Reserve, the Department of Energy, DoJ, HHS, NIH, the U.S. Senate, and academic institutions. QScan exploits vulnerable IoT devices, feeding them into QTRouter, an OpenWrt-based proxy obfuscation network likened to an operational relay box (ORB) that masks attack origins. The group exploited zero-days such as Ivanti CSA flaws CVE-2024-8190, CVE-2024-8963, and CVE-2024-9380, plus numerous N-days, and maintained persistence with RATs, web shells, and legitimate credentials.
Officials disrupt Chinese espionage operation that hit multiple federal agencies
FBI and DOJ seized QTFY infrastructure, disrupting a Chinese state-sponsored group that compromised federal agencies and critical infrastructure since 2018.
Authorities seized three domains powering QScan and QTRouter, the hacking suite of QTFY, a Chinese government-funded group operating through front company Nanjing Xinjiuwei Network Technology. Targets include the Departments of Energy, Justice, and Health and Human Services, the Federal Reserve, NASA, NIH, financial institutions, defense contractors, utilities, telecoms, and hospitals; the group exploited zero-days in Ivanti, Pulse Secure, Fortinet, Citrix, and others, intruding three DOE national labs in September 2024. QScan carried over 200 proof-of-concept exploits and processed more than two million scanning tasks in a single day in 2024.
FBI Seizes China-Linked Hacking Platforms QScan and QTRouter Used Against Critical Infrastructure
FBI seizes China-linked QScan and QTRouter hacking platforms used by QTFY to obfuscate intrusions against US federal agencies.
The DOJ and FBI seized domains hard-coded into QScan and QTRouter, two platforms operated by China-based Nanjing Xinjiuwei Network Technology Company on behalf of state-sponsored group QTFY. QScan automatically infected thousands of IoT devices which were added to QTRouter, an obfuscation network routing malicious traffic through compromised and proxy devices outside China. Targets included NASA, the Federal Reserve, Departments of Energy, Justice, and HHS, NIH, and the US Senate, exploiting flaws in Fortinet SSL-VPN, Citrix ADC, Microsoft Exchange, F5 BIG-IP, Log4j, and others.