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.
Citrix NetScaler ADC and Gateway flaws enable memory information disclosure and user session mix-up; no active exploitation is observed yet.
Citrix patched CVE-2026-3055 (CVSS 9.3), an out-of-bounds read that can expose sensitive memory on systems configured as a SAML Identity Provider, and CVE-2026-4368 (CVSS 7.7), a race condition causing user session mix-up on Gateway and AAA virtual server configurations. Affected builds include NetScaler ADC and Gateway versions prior to 14.1-66.59 and 13.1-62.23. At publication there was no public evidence of active exploitation; CERT-EU recommends prioritizing internet-facing appliances, applying the Global Deny List mitigation, and terminating all sessions after patching.
Unauthenticated .NET Deserialization RCE in Ajax.NET Professional (ajaxpro.2)
Ajax.NET Professional (distributed as the ajaxpro.2 package) is vulnerable to insecure deserialization (CWE-502): it deserializes arbitrary .NET classes supplied by the client without validating which types may be instantiated. Because AjaxPro exposes HTTP endpoints for browser-to-server AJAX calls, a remote, unauthenticated attacker can send a crafted serialized payload to any reachable AjaxPro endpoint and abuse .NET deserialization gadget chains to execute code on the server. Successful exploitation yields full remote code execution with high impact on confidentiality, integrity, and availability (CVSS 3.1 score of 9.8, network vector, no privileges or user interaction required). Any application running any version of ajaxpro.2 / Ajax.NET Professional is affected; the provided data specifies no fixed version, so defenders must rely on vendor guidance for patched releases. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2026-08-26, carries an EPSS 30-day exploitation probability of 83.6%, has public PoC code available, and Talos Intelligence reporting links it to the Chinese-speaking threat actor UAT-10147, which deploys the SPECTRE malware with an EDR bypass and a Linux rootkit in post-compromise operations.
· michaelschwarz (ajaxpro.2 project) ajaxpro.2 (package) All versions are vulnerable; no fixed version specified in the provided data · michaelschwarz Ajax.NET Professional All versions are vulnerable; no fixed version specified in the provided data KEV PoC ×2
Out-of-Bounds Read in Citrix NetScaler ADC and Gateway When Used as SAML IDP
CVE-2026-3055 is an out-of-bounds read (CWE-125) in Citrix NetScaler ADC and NetScaler Gateway caused by insufficient input validation when the appliance is configured as a SAML Identity Provider (IDP). An unauthenticated remote attacker can trigger the flaw by sending crafted input to the SAML IDP functionality, causing the appliance to read beyond the bounds of allocated memory and potentially disclose sensitive information from it. The CVSS 4.0 base score of 9.3 (critical) reflects a network-vector flaw requiring no privileges or user interaction. Only organizations running NetScaler ADC or NetScaler Gateway appliances with SAML IDP configured are affected, according to the available data. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2026-03-30, carries an 87.2% EPSS probability of exploitation within 30 days, has a public proof-of-concept, and headlines indicate active reconnaissance and exploitation against NetScaler deployments, including federal patch directives.
Remote Code Execution in Microsoft SQL Server 2016 and 2017
CVE-2019-1068 is a remote code execution vulnerability in Microsoft SQL Server caused by improper handling of the processing of internal functions (CWE-20, improper input validation). An attacker who can reach SQL Server over the network with low-privileged credentials can trigger the flawed code path and execute arbitrary code, gaining high confidentiality, integrity, and availability impact on the database host. Any organization running affected Microsoft SQL Server versions — including SQL Server 2016 and SQL Server 2017 — is affected. The flaw carries a high EPSS score (52.8% probability of exploitation within 30 days, 99th percentile) and CISA added it to the Known Exploited Vulnerabilities catalog on 2026-08-26, with headlines reporting it being exploited in active attacks. No public proof-of-concept is known, but the in-the-wild exploitation documented by CISA makes patching urgent; the fix shipped in Microsoft's July 2019 Patch Tuesday security updates.
· Microsoft SQL Server · microsoft SQL Server 2016 KEVmass
Memory Buffer Overflow in Citrix NetScaler ADC/Gateway Exploited in the Wild
CVE-2026-8452 is a memory buffer overflow (CWE-119) in Citrix NetScaler ADC and NetScaler Gateway that applies when the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, or RDP Proxy) or as an AAA virtual server. The flaw is reachable over the network without authentication (CVSS 4.0: AV:N/PR:N), so an unauthenticated attacker can trigger it remotely. Successful exploitation causes unpredictable or erroneous appliance behavior and denial of service, and the high confidentiality score suggests possible disclosure of memory contents; some reporting suggests pre-authentication remote code execution may be possible, though the vendor description emphasizes DoS. Organizations running affected NetScaler appliances in a Gateway or AAA role — a very common configuration for remote access to Citrix virtual apps and desktops — are potentially exposed. The flaw was added to CISA's KEV catalog on 2026-08-26 and is reported as exploited in the wild, with headlines noting the flaw was already patched before exploitation was confirmed.
Out-of-Bounds Write in Linux Kernel watch_queue Enables Local Privilege Escalation
CVE-2022-0995 is an out-of-bounds (OOB) memory write in the Linux kernel's watch_queue event notification subsystem (CWE-787) that can overwrite parts of kernel state. A local user can trigger it through the watch_queue interface, for example by supplying a crafted event filter definition, causing the kernel to write beyond allocated memory when event notifications are processed. Successful exploitation may allow the local user to gain privileged (kernel/root) access or crash the system, yielding high impact on confidentiality, integrity, and availability (CVSS 3.1: 7.8, local attack vector). Affected systems include mainstream Linux kernels (Fedora is explicitly listed) and NetApp HCI appliance firmware products that ship the affected kernel. The flaw is confirmed exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2026-08-26, two public proof-of-concepts are available, and EPSS puts 30-day exploitation probability at 9.5% (95th percentile), though ransomware use is unconfirmed.
· Linux kernel Kernels shipping the watch_queue event notification subsystem prior to patched/upstream fixes (see distribution advisories for exact affected and fixed versions · Fedora Project Fedora Fedora releases with affected kernel packages prior to the issued kernel updates (see Fedora/Red Hat advisories) KEV PoC ×2mass
Race Condition in Red Hat libuser Allows Local Privilege Escalation
CVE-2015-3246 is a race condition in Red Hat's libuser, the user-management library used by utilities that modify system accounts, that can cause corruption of the /etc/passwd file during concurrent account updates. An authenticated local user who triggers the race — typically by racing account-modification operations against one another — can desynchronize or corrupt the passwd file. Successful exploitation yields either a denial-of-service condition on the host or, in the privilege-escalation case, elevated (root-level) access by manipulating entries in /etc/passwd. Any Red Hat system shipping the vulnerable libuser library is affected, with risk concentrated on multi-user servers where untrusted local accounts exist. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2026-08-26, indicating it is being exploited in the wild, and EPSS assigns it an 8.8% probability of exploitation within 30 days (95th percentile); ransomware use is unknown and no public proof-of-concept is cataloged.
· Red Hat libuser Affected versions not enumerated in the source data; applies to libuser as shipped with Red Hat distributions and remediated via Red Hat security updates KEVmass
Local Privilege Escalation via Symlink Attack in Red Hat ABRT
CVE-2015-5287 is a privilege escalation flaw in Red Hat's Automatic Bug Reporting Tool (ABRT) in which a local user with certain permissions can gain elevated privileges via a symlink attack against a file with a predictable name. Exploitation requires local access to an affected system; an attacker who triggers the flawed file-handling behavior can elevate their privileges on that machine. It affects deployments running ABRT, which ships by default with Red Hat Enterprise Linux and related distributions, including systems that may now be end-of-life or end-of-service. CISA added the flaw to its Known Exploited Vulnerabilities catalog on 2026-08-26, indicating exploitation has been observed in the wild, though no public proof-of-concept is known and ransomware use is unknown. EPSS estimates a 5.0% probability of exploitation within 30 days (92nd percentile).
· Red Hat Automatic Bug Reporting Tool (ABRT) KEVmass
Race Condition in NetScaler ADC and NetScaler Gateway when appliance is configured as Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server leadin
Race Condition in NetScaler ADC and NetScaler Gateway when appliance is configured as Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server leading to User Session Mixup
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