CISA added actively exploited Cisco FMC, Chrome V8, Fortinet and Citrix NetScaler flaws to its KEV catalog, ordering federal patching by September 12.
CISA added four actively exploited vulnerabilities to its Known Exploited Vulnerabilities catalog. CVE-2026-20079 (CVSS 10.0) is an unauthenticated authentication bypass in Cisco Secure Firewall Management Center's web interface enabling script execution and potential root access. CVE-2026-87491 (CVSS 8.8) is an out-of-bounds write in Chrome's V8 engine — the seventh actively exploited Chrome zero-day of 2026 — fixed in Chrome 153.0.8010.36. CVE-2025-25249 (CVSS 8.1) is a heap-based buffer overflow in FortiOS/FortiSwitchManager's cw_acd daemon being exploited with the PivotC2 RAT, and CVE-2026-19490 (CVSS 9.3) is a NetScaler SAML HTTP-Redirect authentication bypass; federal agencies must patch by September 12, 2026.
CISA adds exploited Citrix NetScaler authentication bypass CVE-2026-19490 to the KEV catalog; federal agencies must patch by September 12.
CISA added CVE-2026-19490, a CWE-288 authentication bypass affecting NetScaler ADC and Gateway deployments configured as AAA virtual servers or Gateway services (including SSL VPN, ICA Proxy, and RDP Proxy), to the Known Exploited Vulnerabilities catalog. Citrix released fixes on August 19, 2026; honeypots recorded 56 attack attempts between September 3 and 8 after a public PoC, though no confirmed production compromises have been reported. Affected builds include 14.1 before 14.1-73.32 and 13.1 before 13.1-63.21; newer installations require SAML IdP configuration to be exposed.
CISA added critical Citrix NetScaler flaw CVE-2026-19490 (CVSS 9.3) to its KEV catalog after confirming exploitation of gateway and AAA virtual servers in the wild.
CISA warned that threat actors are exploiting CVE-2026-19490, a critical-severity flaw (CVSS 9.3) affecting NetScaler ADC and NetScaler Gateway appliances configured as a gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server. Citrix patched the bug on August 19, and Rapid7 warned it is remotely exploitable without authentication. Sensor data from Previdian shows exploitation ongoing since at least September 3, one day after a public exploit appeared on GitHub, with matching requests observed from three IPs across three countries. CISA added the flaw to its Known Exploited Vulnerabilities catalog, giving federal agencies three days to patch under BOD 26-04.
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.
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.
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.
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.
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.
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.
Canada's Cyber Centre updates Citrix advisory as CVE-2026-8451 and CVE-2026-8452 in NetScaler ADC/Gateway are confirmed exploited in the wild.
The Canadian Centre for Cyber Security updated advisory AV26-645 on August 26, 2026, covering critical vulnerabilities in Citrix NetScaler ADC and Gateway (versions 14.1 before 14.1-72.61 and 13.1 before 13.1-63.18, plus FIPS builds). Open-source reporting indicates CVE-2026-8451 and CVE-2026-8452 are being exploited in the wild. Update 3 references related CISA action, and patched builds were released starting June 30, 2026.
Citrix patched a critical authentication bypass, CVE-2026-19490, in NetScaler Gateway and NetScaler ADC, urging customers to upgrade immediately.
Citrix has patched two flaws in NetScaler ADC and NetScaler Gateway. CVE-2026-19490 is a critical authentication bypass (CVSS v4.0 9.3) that works when the appliance is configured as an SSL VPN, ICA Proxy, CVPN, RDP Proxy Gateway or AAA virtual server, with additional conditions depending on firmware and SAML configuration. A second flaw, CVE-2026-19489 (CVSS 8.8), is a memory overflow that can cause denial of service when SIP ALG is enabled on LSN setups. Rapid7 had not observed exploitation as of August 19, 2026, but urged emergency patching; a signature-based mitigation is available via NetScaler Console.
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.
On 19 August 2026 Citrix published an advisory fixing two critical-severity issues in NetScaler ADC and NetScaler Gateway versions 14.1 before 14.1-73.32 and 13.1 before 13.1-63.21, plus FIPS/NDcPP builds. CVE-2026-19490 (CVSS 9.3) is an authentication bypass via alternate path, exploitable when the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server, with a SAML action condition on newer builds. CVE-2026-19489 (CVSS 8.8) is a memory overflow causing unpredictable behaviour or denial of service, requiring SIP ALG enabled on a Large Scale NAT group. CERT-EU recommends applying updated builds as soon as possible.
Remote Authentication Bypass in Citrix NetScaler ADC and NetScaler Gateway
Citrix NetScaler ADC and NetScaler Gateway contain an authentication-bypass vulnerability (CWE-288, 'using an alternate path or channel') that an unauthenticated remote threat actor can exploit. The flaw is triggerable when the appliance is configured as an AAA virtual server or as a Gateway, including SSL VPN, ICA Proxy, CVPN, or RDP Proxy deployments, allowing the attacker to bypass authentication without valid credentials. A successful bypass could give an attacker access to VPN-protected or AAA-gated resources as an authenticated user; no CVSS score has been published yet. Organizations running affected NetScaler appliances in these configurations are exposed, and affected version ranges are not specified in the available data, so defenders should consult Citrix advisory AL26-019. The flaw was added to CISA's KEV on 2026-09-09, indicating exploitation in the wild; ransomware use is unknown, no public PoC is known, and EPSS assigns a 3.4% probability of exploitation within 30 days (88th percentile).
· Citrix NetScaler ADC and NetScaler Gateway KEV PoC large
Unauthenticated Buffer Overflow in Citrix NetScaler ADC and NetScaler Gateway
CVE-2026-19489 is a vulnerability in Citrix NetScaler ADC and NetScaler Gateway classified as a classic buffer overflow (CWE-120), meaning input is copied into a buffer without adequate size checks; it was disclosed by Citrix alongside CVE-2026-19490, the authentication bypass receiving most of the headline attention. Per the CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N), the flaw is reachable over the network by an unauthenticated remote attacker with no user interaction, though detailed trigger conditions are not spelled out in the CVE description. The scoring (VC:L/VI:L/VA:H, base 8.8 High) indicates the primary impact is to availability — likely crashes or denial of service on the appliance — with low confidentiality and integrity impact. All organizations running NetScaler ADC or NetScaler Gateway 14.1 releases through build 73.32, or 13.1 releases through build 63.21, fall within the affected ranges. There is no evidence of exploitation so far: the issue is not in CISA KEV, has no known public proof-of-concept, and EPSS estimates only a 0.4% probability of exploitation in the next 30 days (32nd percentile).
· Citrix NetScaler ADC (formerly Citrix ADC) 14.1 releases through build 73.32; 13.1 releases through build 63.21 · Citrix NetScaler Gateway (formerly Citrix Gateway) 14.1 releases through build 73.32; 13.1 releases through build 63.21mass
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.
Authentication bypass to root access in Cisco Secure Firewall Management Center
CVE-2026-20079 is an authentication bypass (CWE-288) in the web interface of Cisco Secure Firewall Management Center (FMC) Software, caused by an improper system process created at boot time. An unauthenticated, remote attacker can exploit it by sending crafted HTTP requests to the FMC web interface, which allows the execution of script files and commands on the device. A successful exploit grants the attacker root access to the underlying operating system, giving full control of the management platform (CVSS 3.1: 10.0, network-exploitable, no privileges or user interaction required, scope changed). The flaw affects Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management deployments. Cisco has confirmed the vulnerability is being exploited in active attacks, it carries a 35.9% EPSS score (98th percentile), and CISA added it to the Known Exploited Vulnerabilities catalog on 2026-09-09.
Heap-Based Buffer Overflow in Fortinet FortiOS, FortiSwitchManager, and FortiSASE
CVE-2025-25249 is a heap-based buffer overflow (CWE-122/CWE-787) in Fortinet FortiOS, FortiSwitchManager, and FortiSASE that allows an attacker to execute unauthorized code or commands. It is triggered by sending specially crafted packets to an affected device, causing an out-of-bounds write in heap memory that can be leveraged for code execution. Successful exploitation gives attackers command execution on the appliance; in observed intrusions against FortiGate firewalls, attackers have deployed custom Node.js malware and a post-exploitation RAT dubbed PivotC2. Any organization running the affected Fortinet products is at risk, with internet-facing FortiGate firewalls the primary concern. The flaw was added to CISA's KEV on 2026-09-09, confirming active exploitation in the wild (ransomware use unknown); no public PoC is known.
· Fortinet FortiOS · Fortinet FortiSwitchManager KEV PoC mass
Insufficient input validation in NetScaler ADC and NetScaler Gateway leading to memory overread if NetScaler ADC or NetScaler Gateway is configured as a SAML ID
Insufficient input validation in NetScaler ADC and NetScaler Gateway leading to memory overread if NetScaler ADC or NetScaler Gateway is configured as a SAML IDP
Unauthenticated RCE in Gitea via diffpatch API Git Hook Injection
Gitea before 1.27.1 contains a critical code injection flaw (CWE-94) in the diffpatch API that allows remote code execution by causing the installation of a Git hook. An attacker can submit a crafted request through the diffpatch API to plant a Git hook, which then executes arbitrary shell commands on the server when Git operations run; the CVSS vector indicates the attack requires no authentication or user interaction, while public reporting describes attackers with repository write access planting hooks to run shell commands. Successful exploitation yields full server compromise (confidentiality, integrity, and availability all rated high), and observed attacks have reportedly dropped a cryptocurrency miner. All Gitea deployments running versions prior to 1.27.1 are affected, with internet-facing instances at greatest risk; public scans identified over 8,300 vulnerable Gitea servers. The flaw is actively exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2026-08-25, and EPSS estimates an 86.8% probability of exploitation within 30 days.
· Gitea all versions before 1.27.1 KEV PoC ×4moderate
Actively Exploited Out-of-Bounds Write in Google Chrome V8
CVE-2026-87491 is an out-of-bounds write (CWE-787) in the V8 JavaScript engine in Google Chrome, fixed in Chrome 153.0.8010.36, which Google shipped alongside roughly 230 other security fixes. An attacker can trigger the flaw remotely by luring a user (user interaction required) into opening a crafted HTML page that corrupts memory in V8. Successful exploitation allows the attacker to execute arbitrary code inside the Chrome browser sandbox, which constrains but does not eliminate the impact. All Google Chrome users running versions prior to 153.0.8010.36 are affected; because the flaw resides in V8, CISA tracks it as 'Google Chromium V8', and other Chromium-based browsers may inherit the fix in their own updates. The flaw is being actively exploited in the wild — it is the seventh actively exploited Chrome zero-day of 2026 and was added to CISA's KEV catalog on 2026-09-09 — though no public proof-of-concept is known and ransomware use is unknown.
· Google Chrome (V8 JavaScript engine; tracked by CISA as 'Google Chromium V8') prior to 153.0.8010.36 KEVmass
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
Entities are extracted by the model from each article. Watching an entity keeps it in this browser only (no account); the watchlist page and dashboard alerts use it.