U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Atlassian flaw to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added an Atlassian flaw, tracked as CVE-2026-21589 (CVSS score of 9.3), to its Known Exploited Vulnerabilities (KEV) catalog. In early October, threat actors started exploiting CVE-2026-21589, a critical arbitrary file access flaw in Atlassian Data Center products. The vulnerability could allow attackers to access sensitive files under certain conditions. Affected products include Bitbucket, Confluence, Jira Service Management, Jira Software, Bamboo, Crowd, Crucible, and Fisheye. “This Arbitrary File Access vulnerability allows an unauthenticated attacker to access specific files within the web application root directory in affected versions. Exploitation requires prior knowledge of the target file’s exact name and path; this vulnerability does not allow attackers to enumerate or list directory contents.” reads the advisory. “In some configurations, there may be some sensitive files that make this highly severe.” Previdian telemetry has detected 15 exploitation attempts from three IP addresses in Japan and the U.S.. “Exploitation has now started to hit our honeypot network” Previdian Founder Ryan Dewhurst wrote on LinkedIn. On October 6, watchTowr Labs published a technical analysis of CVE-2026-21589 after comparing vulnerable and patched Atlassian packages. Researchers found a path traversal flaw where double-colon (::) sequences can be treated as path separators, allowing attackers to read files from the application web root. “While semicolons (;) are very common in path traversal within Java applications, along with the everyday dots (.) and slashes (/), one item stood out: the matching of double colons (::).” reads the analysis. “This is uncommon syntax for this type of vulnerability, but grepping through the codebase we came across an all too familiar sight.” In one Crowd deployment with Jira, researchers were able to read crowd.properties, which exposed application credentials. They then used those credentials to create a user and add it to the jira-administrators group. Crowd IP allowlisting can block this attack path. Exploitation attempts against its honeypot network reportedly began two hours after watchTowr published additional technical details about the vulnerability. According to watchTowr, the problem is in Atlassian’s web-resource handling. It can turn a string such as ..::..::..::..::WEB-INF::web.xml into ../../../../WEB-INF/web.xml, allowing attackers to move through directories and access files they should not be able to read. Atlassian says all versions before the listed fixed versions are affected: ProductFixed versionsBitbucket Data Center9.4.26, 10.2.8, 10.5.1Confluence Data Center9.2.26, 10.2.19Jira Service Management Data Center5.12.40, 10.3.26, 11.3.12Jira Software Data Center9.12.40, 10.3.26, 11.3.12Bamboo Data Center10.2.24, 12.1.12Crowd Data Center6.3.7, 7.0.3, 7.1.7, 7.2.4Crucible4.9.15Fisheye4.9.15 watchTowr has released a free tool on GitHub to help check if a server is vulnerable. According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog. Experts also recommend that private organizations review the Catalog and address the vulnerabilities in their infrastructure. CISA orders federal agencies to fix the flaw by October 18, 2026. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, CISA)
Microsoft says some users may have trouble turning on Smart App Control after installing this month's KB5127648 Windows 11 security update. Smart App Control is a Windows 11 security feature that uses Microsoft's app intelligence services and code integrity features and works alongside Microsoft Defender and SmartScreen to block potentially harmful apps or binaries. According to the company, on affected devices running Windows 11, version 24H2 and later, the Smart App Control option is grayed out and cannot be toggled. "After installing this update, some devices might be unable to turn on Smart App Control in the Windows Security app if it has been turned off. On affected devices, the option to turn on Smart App Control might be grayed out," Microsoft said in an update to the KB5127648 advisory.
The Administrative Office of the US Courts says a cyberattack on government contractor BAE Systems has taken down the notice system used by federal bankruptcy courts. In a Thursday press release, the Administrative Office of the US Courts said the BAE Systems cyberattack also halted the production and distribution of bankruptcy notices. "The Administrative Office of the US Courts has been in communication with the impacted courts and is also coordinating with BAE Systems. BAE is actively investigating this incident and working to restore operations," it said. "As a result of the incident, all access to the BNC systems and websites that BAE operates on behalf of the Judiciary and the related bankruptcy noticing process are unavailable at this time, including bnc.uscourts.gov, bankruptcynotices.uscourts.gov, notices.uscourts.gov, and the National Creditor Registration Service."
BeyondTrust warned customers on Thursday to patch a critical flaw in its Remote Support (RS) that has been exploited in zero-day attacks since late August. Remote Support is the company's enterprise-grade support solution that helps IT service desks, help desks, and customer support teams troubleshoot issues remotely. Tracked as CVE-2026-102764, this actively exploited authentication bypass vulnerability lets unprivileged remote attackers perform file operations on unpatched appliances and affects RS 26.2.3 or earlier. BeyondTrust patched the security issue for all Remote Support and Privileged Remote Access SaaS customers on October 8, but self-hosted installations must be patched manually if automatic updates are not enabled. While the company shared limited details about the vulnerability, it said the zero-day was abused in the wild by a suspected China-nexus espionage actor tracked by Mandiant and Google Threat Intelligence Group (GTIG) security researchers as "Armory Castle" (formerly UNC5221) and by cybersecurity firm CrowdStrike as "Warp Panda."
In the space of a month, a new category of AI model went from nonexistent to everywhere. TypeSafe AI released Jev on September 15 and called it a System One model, a nod to Kahneman's fast, intuitive thinking. OpenAI announced its own Decisions API at DevDay and opened a public beta on October 6. Cribl published cribl-decision, an open LoRA adapter you can run locally. Others, like Laya, are
The China-nexus cyber espionage group tracked as Armory Castle (previously UNC5221 or Warp Panda) exploited a newly disclosed security flaw in BeyondTrust Remote Support (formerly Bomgar) as a zero-day in late August 2026. The vulnerability, tracked as CVE-2026-102764 (CVSS score: 9.3), is a case of improper origin validation in an internal messaging component that could be exploited by a
AI agents being tested online reached the live systems of Indian organizations and read business records, including personal data and confidential material, CERT-In said in an advisory on October 15. The agents went beyond their assigned tasks, and none of the organizations detected the unauthorized access. After internal reviews, the AI companies whose models were being tested
Our analysis an AI-powered espionage campaign targeting government Linux infrastructure with custom malware, web shells, and advanced credential theft. The post AI-Powered Espionage Campaign Targets Government Linux Infrastructure appeared first on Unit 42.
Threat actors are exploiting a critical command execution flaw, now tracked as CVE-2026-110447, in the Collabora Online - Built-in CODE Server app (richdocumentscode) for Nextcloud. Multiple administrator reports indicate that attacks began in mid-September, roughly a month before the formal security bulletin, the GitHub advisory, and CVE publication. CVE-2026-110447 impacts richdocumentscode versions before 26.4.303 and resides in the Nextcloud app’s mechanism for starting the bundled Collabora server. The flaw affects only the optional built-in CODE server app. Standalone Collabora Online servers, Docker and RPM/DEB installations, and Nextcloud All-in-One deployments remain unaffected, according to Collabora. The attacks involve sending a malicious request to the app’s proxy.php endpoint, triggering OS command injection.
Silent Lynx, a group likely based in Kazakhstan, targets Russian energy and government entities in espionage campaigns across Central Asia. Researchers from Cisco Talos and Recorded Future published a detailed paper on a threat actor they call Silent Lynx (aka UAT-6275, TAG-193), a Kazakhstan nexus group conducting espionage across Central Asia. The targets include the Orsk Oil Refinery in southern Russia, about 25 kilometers from the Kazakhstan border, and the government of Nizhny Novgorod, a major city about 425 kilometers east of Moscow. The city lies where the Volga and Oka rivers meet, an important waterway system connected to the Caspian Sea. This target may be significant because Kazakhstan depends on the Caspian basin. The group has been running targeted intrusion campaigns against government bodies, diplomatic missions and civil society organizations across Central Asia since at least 2024. “Silent Lynx (overlapping with activity tracked as UAT-6275 by Cisco Talos and as TAG-193 by Recorded Future) is a persistent threat actor that has conducted targeted intrusion campaigns against government ministries, diplomatic missions and civil society organizations across Central Asia since at least 2024.” the paper states. “The group maintains a strong focus on high-value public sector organizations in the Commonwealth of Independent States (CIS), frequently leveraging spear-phishing campaigns conducted through compromised government email accounts and malware staging through trusted public services such as GitHub to increase credibility and infection success rates.” The group overlaps significantly with clusters previously documented under names like YoroTrooper, ShadowSilk, and Hydra Saiga, all pointing at the same underlying activity. The toolkit is deliberately lightweight: PowerShell-based reverse shells, proprietary shells written in C++, C#, and Go, commodity tunneling tools, and spear phishing emails sent through compromised government email accounts in Tajikistan and Kyrgyzstan to add credibility. GitHub, Telegram, and hijacked legitimate servers all serve as staging platforms. Nothing about it is technically flashy, which is part of why the group has stayed active for years without much public attention. The researchers found links that go beyond technical evidence. In March 2026, a Tajik government agency contacted a Silent Lynx server, shortly after Kazakhstan’s lower house of parliament ratified a Treaty on Allied Relations with Tajikistan. In early April, a Belarusian government entity appeared on the same infrastructure, about a week before Kazakhstan’s president met with the Belarusian foreign minister in Astana. These links do not prove the reasons behind the activity, but the researchers highlight them in their paper, and they are difficult to ignore. The connection to the Orsk refinery also has a clear context. A Ukrainian drone attack in August forced the refinery to shut down for months. Russia had already asked Kazakhstan to help make up for the resulting loss of refining capacity. If a Kazakhstan-linked actor was collecting intelligence on Russian energy infrastructure at that time, it could have been assessing the economic impact or trying to understand how the disruption might affect Kazakhstan’s own export pipelines. The researchers stress that they do not have enough evidence to identify a specific motive. However, they present the facts and let readers draw their own conclusions. “A sample compiled in August 2025 was observed using a document titled Деловое предложение о сотрудничестве между ГК «Туркменнебит» и руководством Орского НПЗ (translated: Business proposal on cooperation between State Concern ‘Turkmennebit’ and the management of Orsk Refinery) (see Figure 11). We assess that this sample may be targeting Russia’s critical energy infrastructure, given the close integration of the Russian BREAK THE SILENCE: TRACKING SILENT LYNX THROUGH EXPOSED INFRASTRUCTURE SHEN & VÖGELE 10 VIRUS BULLETIN CONFERENCE OCTOBER 2026 and Kazakh energy sectors.” continues the report. “The document outlines proposals for developing mutually beneficial cooperation, with a particular focus on the exchange of expertise, technologies, and industry best practices. It is worth noting that the author of this PDF file is ‘pickle rick’ and the document was created just one hour after the payload was compiled. The name ‘pickle’ is aligned with the name ‘pickl’ we observed in the PickleShell PDB string3.” What gave the group away wasn’t a sophisticated interception, it was their own operational sloppiness. They left open directories exposed on public servers containing live tooling, staged payloads, and one very incriminating shell command history showing keyboard input typed in Latin with a Russian keyboard layout active, so “whoami” came out as “црщфьш.” GitHub commit timestamps across 77 commits fit working hours in Astana, Kazakhstan, at 95 percent, compared to only 51 percent if you plot them against Moscow time. Administration connections to Silent Lynx servers came from ProtonVPN egress IPs geolocated to Kazakhstan, exclusively on weekdays between 7 AM and noon local time. The group’s servers were also being reached from those VPN addresses, which Proton typically assigns based on geographic proximity. Two malware samples were uploaded to VirusTotal from Kazakhstan within minutes of compilation, which is classic anti-detection testing behavior and points to the operator location directly. “We identified several additional indicators that strengthen the assessment of a Kazakhstan-based origin. The first derives from what appears to be malware detection-testing activity conducted through VirusTotal.” continues the report. “Two samples showed this pattern: an early Chvost sample12 was uploaded to VirusTotal only 86 seconds after compilation, while a second sample13 was uploaded approximately four minutes after compilation. Both samples were uploaded from Kazakhstan, and the same uploaders had submitted additional tools that were later observed in Silent Lynx campaigns.” A researcher at Johns Hopkins School of Advanced International Studies told Reuters that the case highlights an important point: cyber espionage is no longer the domain of a few major powers. Smaller countries are also developing their capabilities and running long-term operations against neighboring states, often driven by serious geopolitical interests. Silent Lynx is also becoming more technically advanced. In April 2026, the group used an exploit for the first time to deliver malware. It abused a WinRAR path traversal flaw (CVE-2025-8088) to place malicious files directly in the Windows Startup folder, without requiring victims to enable macros. The group also stored a public proof of concept for a FortiWeb authentication bypass vulnerability on its own command-and-control (C2) server. Researchers have also found signs of growing interest in Linux systems. After relying mainly on social engineering for two years, Silent Lynx appears to be building a more advanced set of attack tools. Full joint Virus Bulletin paper with full indicators of compromise, malware hashes, and infrastructure details is available here. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, SILENT LYNX)
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