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Attackers are exploiting a new critical zero-day flaw in Cisco Catalyst SD-WAN Manager, the system companies use to manage their Cisco SD-WAN networks, Cisco said in an  advisory  on September 30. The flaw, CVE-2026-76504 , could allow a remote attacker with no login access to use the Manager's API as the admin user. Fixed releases are available, and there is no workaround. It carries a CVSS score of 9.8 out of 10. It sits in the part of the Manager's API that handles login sessions. The Manager mishandles URI encoding in an HTTP request. A crafted request can therefore bypass an authentication rule intended to restrict access to a single API endpoint. The attacker needs no credentials, only the ability to send that request to the Manager's API. Managers exposed to the internet are at risk of compromise, according to Cisco. By default, the admin user holds the netadmin role, which is allowed to perform all operations on the device. Cisco said its Product Security I...

Unknown threat actors have been observed exploiting a newly patched security flaw in Citrix NetScaler ADC and NetScaler Gateway appliances to target organizations in North America and Europe. The activity, observed by Mandiant Consulting and Google Threat Intelligence Group (GTIG) in September 2026, has targeted government, financial services, technology, education, and legal and professional services sectors. In a post shared on LinkedIn, Charles Carmakal, chief technology officer at Mandiant Consulting, said the targeted intrusions have impacted dozens of organizations, warning of "broad and opportunistic exploitation of CVE-2026-88772 and CVE-2026-88771 by a variety of threat actors in the near term." "Exploitation of CVE-2026-88772 bypasses authentication and triggers an unhandled termination of the NetScaler Packet Processing Engine (NSPPE) to establish initial root-level access," the tech giant said . The attacks have been observed weaponizing the f...

A High-severity OpenSSL flaw can leak heap memory to the other side of a DTLS connection or crash the program,  OpenSSL said  on September 29 as it released fixes. DTLS , the TLS variant used for UDP traffic, resends a handshake message if no reply arrives before the timer expires. The leak or crash can happen when such a resend starts while a larger handshake message is stuck part-way through being sent. The flaw, tracked as CVE-2026-84782, is fixed in  OpenSSL 4.0.3, 3.6.5, 3.5.9 and 3.4.8 . Fixed versions for the older 3.0, 1.1.1 and 1.0.2 branches go only to customers who pay for OpenSSL's premium support. OpenSSL 3.0  stopped getting public security fixes  on September 7. OpenSSL has not said whether an attacker can cause a resend while a message is stuck, nor has it reported any attacks exploiting the flaw. DTLS is used, for example, to protect WebRTC data channels and to set up encryption keys for internet calls. Software is exposed to this fla...

Cybersecurity researchers have disclosed technical details of a recently patched critical security flaw in Citrix NetScaler ADC and Gateway that has come under active exploitation in the wild. The vulnerability, tracked as CVE-2026-88772 (CVSS score: 9.5), has been described as a memory overflow bug in the Datagram Transport Layer Security (DTLS) protocol handling that's rooted in the NetScaler Packet Processing Engine (NSPPE). "Citrix NetScaler ADC and NetScaler Gateway contain an improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for remote code execution or denial-of-service," the U.S. Cybersecurity and Infrastructure Security Agency (CISA) said . The issue, per watchTowr , is that NetScaler implicitly trusts the declared fragment size in the DTLS handshake header's fragment_length field (i.e., 1 byte), while the header simultaneously claims that the complete message, as denoted by the length field, is 120...

An attacker used stolen passwords of staff at France's tax administration to take tax data on hundreds of thousands of taxpayers and businesses in June and July. Neither the tax administration nor France's national cybersecurity agency saw the data leave. The attack was not sophisticated, the agency, ANSSI, says in a  report  (in French) published on Tuesday: it worked because of weak login protection, poorly separated networks and gaps in monitoring. The tax administration, known as the DGFIP, runs France's tax website, impots.gouv.fr. The data came from E-Contact, the tool taxpayers use to message the tax administration. The stolen data covers  a little over 350,000 individuals  and  a little over 250,000 businesses , the DGFIP says. Taxpayers' own online accounts and passwords were not compromised. For individuals, the data that may have been viewed or copied includes their tax ID, contact details, family situation, reference taxable income and tax...

A domain used as harmless placeholder text showed up in roughly 1,700 repositories. Then somebody registered it and started serving malicious lures. That is the kind of week this was: forgotten assumptions turning into live attack surface. Elsewhere, weak service accounts, old bugs, exposed systems, phishing kits, and strangely easy exploit paths kept doing useful work for attackers. Nothing exotic. Mostly things nobody expected to matter anymore. Here’s the full recap of what mattered this week. ⚡ Threat of the Week Citrix Warns of Actively Exploited NetScaler ADC and Gateway Flaws — Citrix released patches to address multiple vulnerabilities, including CVE-2026-88771 and CVE-2026-88772, that have come under active exploitation. CVE-2026-88771 is an improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands, while successful exploitation of CVE-2026-88772 could allow for remote code execution or denial-of-service. CISA...

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Sunday added two critical Citrix NetScaler ADC and Gateway flaws to its Known Exploited Vulnerabilities ( KEV ) catalog, following reports of active exploitation. The vulnerabilities are listed below - CVE-2026-88771 (CVSS score: 9.5) - An improper input validation vulnerability that could allow an unauthenticated attacker to execute arbitrary commands.  CVE-2026-88772 (CVSS score: 9.5) - An improper restriction of operations within the bounds of a memory buffer vulnerability that could allow for remote code execution or denial-of-service. While CVE-2026-88771 affects all NetScaler ADC and NetScaler Gateway deployments, CVE-2026-88772 requires the DTLS configuration to be enabled on NetScaler ADC or NetScaler Gateway, an option that is turned on by default on VPN virtual servers. The relevant configuration is as follows - add vpn vserver vpn1 SSL 10.0.0.0 443 -Listenpolicy NONE 

Two critical vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway that allow remote code execution have been exploited in the wild, Citrix confirmed on September 27. It released fixes for both, along with six other flaws. One of the two affects every deployment on an affected version, including those in the default configuration. The bulletin came a day after security firm watchTowr said two unpatched NetScaler RCE flaws had been exploited, and after some administrators said they had taken appliances offline. Citrix did not say whether its two flaws are the ones watchTowr described, but they match that account. NetScaler ADC and NetScaler Gateway sit at the edge of enterprise networks, where they handle VPN and remote access, load balancing, and user authentication. Citrix said in its bulletin that the two exploited flaws are: CVE-2026-88771 (CVSS v4 score: 9.5) - An improper input validation flaw that lets an unauthenticated attacker run arbitrary commands. It a...

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Friday added two security flaws impacting Microsoft SharePoint and Mikrotik RouterOS to its Known Exploited Vulnerabilities ( KEV ) catalog, citing evidence of active exploitation. The vulnerabilities in question are as follows - CVE-2026-65660 (CVSS score: 8.8) - A code injection vulnerability in Microsoft Office SharePoint that allows an authorized attacker to execute code over a network. CVE-2026-67279 (CVSS score: 6.9) - An improper enforcement of behavioral workflow vulnerability in  Mikrotik RouterOS that could allow an unauthenticated client to open a session channel and send an exec request. As reported by The Hacker News earlier this week, CVE-2026-65660 was originally described by Microsoft as a spoofing vulnerability impacting SharePoint Server. The tech giant has since updated the advisory to state that it could be abused to obtain remote code execution. "As of 9/25/2026, Microsoft ...

Two MikroTik RouterOS SSH vulnerabilities chained together let attackers take full administrative control of Internet-exposed routers without a password, SSH key, or completed authentication. The chain, which CERT Polska calls MikroTrick , combines an SSH state-machine flaw ( CVE-2026-67279 ) with an argument-injection bug in the RouterOS login process ( CVE-2026-86060 ). Attack logs date to at least September 2, one day before MikroTik shipped patches in RouterOS 6.49.21, 7.23.4, and 7.24.2. As  previously reported , CERT Polska warned on September 5 that attackers were using RouterOS flaws to take control of devices whose SSH service was reachable from public networks. That warning confirmed the exploitation and urged immediate patching but did not identify which two flaws formed the chain or explain how they combined. This latest analysis provides both. How the Chain Works SSH requires three steps in order: it establishes an encrypted connection, authentica...

Attackers are exploiting a critical flaw in F5 BIG-IP Access Policy Manager (APM) that lets them run code on a BIG-IP system without logging in, F5 says. The flaw,  CVE-2026-94127 , affects only systems in which APM serves as an OAuth authorization server, issuing access tokens to applications. F5 disclosed it in  an advisory  on September 22 and has released engineering hotfixes. APM is the BIG-IP module that controls how users reach an organization's applications and networks. The vulnerable setup has an APM access policy and an OAuth authorization server profile on the same virtual server, which hosts the BIG-IP address that receives the OAuth traffic. Specific malicious traffic sent to that virtual server can lead to remote code execution. The flaw is a heap-based buffer overflow. F5 rates it 9.8 out of 10 on CVSS v3.1 and 9.3 on CVSS v4.0. Because the malicious traffic goes to the virtual server itself, limiting access to the BIG-IP management interface does...

Attackers exploited a previously unknown flaw in Check Point's Security Management Server in a handful of targeted attacks on July 23,  the company said . The flaw, CVE-2026-93616 , allows an attacker who can access the server's web service to run scripts on it without logging in. Check Point released a fix on September 22 for the server that controls firewall policies for the Check Point gateways it manages. Separately,  Check Point said  attackers have been trying since September 12 to exploit a VPN flaw it  fixed on September 9 . The attempts, against a flaw tracked as CVE-2026-85102, have targeted customers of Spark, Check Point's firewall line for small businesses. When the fix came out, Check Point had no evidence the flaw was being exploited. CVE-2026-93616 is a path traversal bug in the management server's web service. The service does not properly limit which files and folders a request can reach. An attacker can use it to upload scripts to the s...

Attackers are exploiting a new flaw in on-premises VeloCloud Orchestrator (VCO), the server that manages the Edge devices in a VeloCloud SD-WAN, Arista said on September 22. The flaw, tracked as CVE-2026-93952 , may allow a remote attacker with no login access to privilege internal functions and affect the VCO host. Only orchestrators set up to authenticate their Edges with certificates are exposed. As of September 22,  fixed releases  are out for the 5.2 and 6.4 release trains, but not yet for the 6.1 and 7.0 trains. Arista has already patched the Hosted and Dedicated versions of VCO. The affected releases include those that fixed a different VCO flaw, which Arista reported as  exploited in July . Arista gave the flaw a CVSS 3.1 score of 10.0. A successful attack may compromise the orchestrator and the data it manages. A compromised VCO may also give attackers access to the Edge devices it manages. Arista said the flaw "was discovered externally and is known t...

When the Digital Operational Resilience Act (DORA) became enforceable across the European Union in January 2025, it triggered an administrative sprint. Financial entities spent the first year establishing risk governance, assessing third-party service providers, updating contract clauses, and documenting incident escalation workflows. Now in its second year, the harder part of DORA is demonstrating how well frameworks work in practice. EU regulators are increasing their focus on DORA implementation, Information and Communication Technology (ICT) incident analysis, and the effectiveness of ICT risk supervision. For security teams, that raises an important question: does the SOC have enough visibility to detect, investigate, and scope an active intrusion across critical systems? While DORA doesn’t prescribe a particular security stack, several of its requirements rely on continuous visibility in the ICT environment to identify behavior that may indicate an emerging risk. Continuou...

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Monday added a now-patched security flaw impacting Zyxel GS1900 series switches to its Known Exploited Vulnerabilities ( KEV ) catalog, citing evidence of active exploitation. The vulnerability, tracked as CVE-2026-7273 (CVSS score: 8.8), is a stack-based buffer overflow vulnerability that could result in arbitrary operating system (OS) command execution. "A stack-based buffer overflow vulnerability in the CGI program of the Zyxel GS1900 series switch firmware could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request," Zyxel said in an advisory released in June 2026.  The issue has been addressed in the following versions -

A browser. A plugin. A package. A login screen. Normal stuff. That is basically the problem this week. The trouble keeps showing up inside things people already trust: code that takes a bad turn, old payloads coming back, exposed systems, weak checks, fake fixes, and attack paths that look almost too easy. Even the research side is getting messy, with more findings, more automation, and not always more clarity. Nothing here needs much drama. Just a lot of small doors left open. Here’s what happened. ⚡ Threat of the Week Cisco Warns of Actively Exploited ISE Auth Bypass — Cisco warned of a fresh maximum-severity security flaw impacting Identity Services Engine (ISE) that has come under active exploitation. The vulnerability, tracked as CVE-2026-76460 (CVSS score: 10.0), could allow an unauthenticated, remote attacker to bypass authentication. "This vulnerability is due to insufficient authentication control on an API endpoint," Cisco said. "An attacker could exp...

A security researcher has released working exploit code for four Linux kernel flaws that each let a local user gain root, the highest level of access on a machine. Kernel maintainers have fixed all four over the past few weeks, so a system running an up-to-date kernel is not affected. But the exploit code is now public, and any machine still running an older kernel should be updated. The flaws are called DirtyAH6 , TUNderflow , PPPoEject , and DiagSpill . Researcher Asim Manizada found them and reported them to the Linux kernel security team in mid-July. He published a technical  write-up  with working exploits on September 18, after a coordinated hold with Linux distributions so the fixes could be released first. So far, there are no reports of the four being used in real-world attacks. The exploits are Manizada's own, are tuned to specific kernel builds, and can crash a machine, so they are meant for isolated test systems. Still, public exploit code raises the ris...

A critical vulnerability in Check Point's Security Management and Log Servers could allow an attacker without login credentials to run code as root on those servers over the network. The Security Management Server is the system that controls firewall policy and administrator access. Check Point has released a fix through its LivePatch update channel and says it has no indication that the flaw has been exploited. Check Point told The Hacker News that the vulnerable path runs only through the Trusted Clients setting, which controls which hosts may connect to the management server through SmartConsole. The flaw, tracked as CVE-2026-91843 and rated 9.8 out of 10 on the CVSS scale by Check Point, is a stack overflow in the login process, which handles requests before a user is authenticated. Internet scanning company Censys said the overflow is triggered by a login request that carries a very long username. Check Point said in a notice on its  CheckMates community  on...

Every release of the Unbound DNS resolver before 1.26.1 has a critical heap overflow in its DNSSEC validator, maintainer NLnet Labs said in an  advisory  on Wednesday. An attacker who controls a malicious zone and queries a vulnerable resolver can trigger it, enabling remote code execution. Unbound 1.26.1, released the same day, fixes the bug, tracked as  CVE-2026-81642 , along with eight other flaws. One of the eight,  CVE-2026-82717 , is a heap corruption bug in CNAME synthesis reported by Ben Morris of Anthropic. It could also lead to remote code execution "under certain systems and compilation options," NLnet Labs said. NLnet Labs has not reported exploitation of either bug, and CISA's entry for CVE-2026-81642 marked exploitation as "none" on Wednesday. NLnet Labs rates the DNSKEY flaw Critical, with a CVSS score of 4.0 (9.1), and its scoring lists a network attack vector requiring no privileges or user interaction. NVD listed the CVE as "Await...

The Internet Systems Consortium (ISC) has released  BIND 9.20.29 and 9.21.26  to fix fourteen security flaws it  disclosed  on 16 September in BIND 9, its open-source DNS server software. One of them affects any BIND server that answers DNS-over-HTTPS (DoH). A sender with no credentials can crash the server process, named, with a single request that carries an invalid SIG(0) signature, if the sender closes the connection before named finishes checking the signature. ISC said in its advisories that it is not aware of any of the fourteen being exploited. Which Release Fixes What The fixed releases, described in ISC's  release notes , are: BIND 9.20.29, on the current stable branch: fixes all fourteen BIND 9.21.26, on the development branch: fixes thirteen, because CVE-2026-19662 does not affect 9.21 BIND 9.20.29-S1, the Supported Preview Edition for support customers: fixes all fourteen ISC lists no workarounds for any of the...