Citrix confirmed that two critical NetScaler remote code execution vulnerabilities, CVE-2026-88771 and CVE-2026-88772, are being exploited in attacks, and released fixes. These are the same zero-days that researchers, IT providers, and national cyber agencies warned about privately over the weekend, with some advising immediate NetScaler shutdowns. Organizations commonly deploy NetScaler as internet-facing edge devices for remote access and application delivery, so compromising one gives attackers a foothold at the network perimeter and a potential path to internal systems without first landing on an internal endpoint. CISA added the flaws to its Known Exploited Vulnerabilities catalog with a near-term federal patch deadline.
CISA added a Zyxel GS1900 series switch flaw to its Known Exploited Vulnerabilities catalog, citing active exploitation. Tracked as CVE-2026-7273 and rated 8.8, it is a stack-based buffer overflow in the switch firmware's CGI program that lets a LAN-based, unauthenticated attacker run operating system commands through a crafted HTTP request. Zyxel patched it in June across the GS1900-8 through GS1900-48HPv2 models. GreyNoise reported that a suspected Chinese-speaking actor has weaponized the flaw since August 17, successfully exploiting and exfiltrating data from 996 Zyxel switches across 48 countries. Federal agencies must patch under the KEV directive, and other operators should treat exposed management interfaces as a priority.
CISA has added two critical Fortinet FortiSandbox vulnerabilities to its exploited-vulnerabilities catalog and ordered federal agencies to patch them by July 19. Tracked as CVE-2026-39808 and CVE-2026-25089, both are operating-system command injection flaws that let an unauthenticated attacker run commands remotely with low complexity and no user interaction. Fortinet disclosed and fixed them in April and June, and threat intelligence firm Defused reported in-the-wild abuse of FortiSandbox flaws in June. FortiSandbox is a threat-detection appliance, and Fortinet gear sits at many network edges, so these devices are a recurring target in espionage and ransomware campaigns, making prompt patching important.
CISA has added a Cisco IOS vulnerability to its Known Exploited Vulnerabilities catalog after confirming it is being used in real attacks, requiring federal agencies to patch it under a binding deadline. Cisco IOS and IOS XE run the routers and switches behind many enterprise and service-provider networks, so a flaw here can give attackers a foothold deep in the network path. The listing lands amid heightened warnings, including a joint US-and-allies advisory this week urging better router hygiene against Russian state-sponsored targeting of network devices. Network gear is attractive because it often sits unmonitored, stays online for years, and rarely runs endpoint security; timely patching is the main defense.
CISA has added two actively exploited vulnerabilities to its Known Exploited Vulnerabilities catalog, both in popular Joomla extensions and both allowing attackers to upload dangerous files. The iCagenda event calendar flaw (CVE-2026-48939, rated 10.0) lets an attacker upload arbitrary files through its attachment feature, ending in PHP code execution, while the Balbooa Forms flaw (CVE-2026-56291) allows unauthenticated upload of executable files leading to full remote code execution. Federal agencies were ordered to fix them by July 13. The additions line up with a broader campaign, recently flagged by Australia's cyber agency, in which attackers scan the internet and exploit known content-management-system and plugin flaws to plant web shells on vulnerable sites.
CISA has added a SharePoint remote code execution flaw to its Known Exploited Vulnerabilities catalog after confirming active exploitation, months after Microsoft rated it less likely to be attacked. The bug (CVE-2026-45659, CVSS 8.8) comes from unsafe deserialization of untrusted data and lets an authenticated attacker with only Site Member permissions run code on a SharePoint server over the network, with low complexity and no user interaction. Microsoft patched it in May for SharePoint Server Subscription Edition, 2019, and Enterprise 2016. On-premises SharePoint is a repeated target because it holds sensitive data and is often internet-facing, and it has a long history of weaponized code execution flaws.
CISA has updated its Known Exploited Vulnerabilities catalog to warn that ransomware gangs are now exploiting BlueHammer, a Microsoft Defender privilege-escalation flaw. The bug (CVE-2026-33825) lets a local attacker who already has a foothold escalate to SYSTEM by abusing Defender's file-remediation logic, giving them access to password hashes and the control needed to disable defenses and prepare systems for encryption. It was leaked with proof-of-concept code by a researcher in early April as a protest over Microsoft's disclosure process, exploited as a zero-day, then patched on April 14. It cannot be used for remote compromise on its own, but it strengthens attackers after initial access.
Attackers are actively exploiting a critical flaw in PTC Windchill and FlexPLM, product lifecycle management software widely used across automotive, aerospace, defense, and manufacturing to store designs, engineering data, and intellectual property. The bug (CVE-2026-12569) is an unsafe deserialization issue that lets an unauthenticated attacker run code remotely by sending a crafted request. PTC patched it in mid-June, but has since reported heightened activity, with attackers deploying JSP web shells for command execution and data theft. CISA added it to its Known Exploited Vulnerabilities catalog, the first-ever PTC product to be listed, with a federal deadline of June 28. PTC has published indicators of compromise.
CISA has confirmed active exploitation of four critical flaws in Ubiquiti UniFi OS and Lantronix EDS5000 devices, adding them to its Known Exploited Vulnerabilities catalog with a June 26 deadline for federal agencies. Three UniFi OS bugs (CVE-2026-34908, CVE-2026-34909, CVE-2026-34910), each rated 10.0, can be chained for unauthenticated remote code execution and root; attackers were seen creating rogue admin accounts. The Lantronix flaw (CVE-2025-67038) is an unauthenticated root command injection in the EDS5000 serial console server. Ubiquiti patched UniFi OS Server in version 5.0.8, and Lantronix in firmware 2.2.0.0R1. Compromised network appliances let attackers pivot deep into internal networks.
A critical Splunk Enterprise flaw disclosed earlier this month is now being exploited in the wild, and CISA has added it to its known-exploited list with a June 21 federal patch deadline. The bug (CVE-2026-20253, rated 9.8) is a missing-authentication issue in a PostgreSQL sidecar service: an unauthenticated, network-reachable attacker can create or truncate arbitrary files on the Splunk host, which can cascade into log corruption, broken monitoring, and remote code execution. Both Splunk and Resecurity have confirmed active exploitation, and a public proof-of-concept and Nuclei template exist. Because Splunk underpins many SOC and SIEM operations, a compromise can blind defenders.
TrustStrike Labs