Keycloak Cluster on Three VMs: Engineers Detail Embedded Infinispan Setup, HA Testing Failures, and Bug Fix
A project required centralized authentication and authorization for 25,000–30,000 active users distributed nationwide, demanding strong scalability and reliability. The team selected Keycloak and rejected a single instance because it could not meet throughput or SLA targets. They therefore built a three-node cluster on isolated virtual machines using Embedded Infinispan and JGroups.
Kubernetes was considered excessive for the environment. The chosen architecture placed each Keycloak node in a separate data center, shared a PostgreSQL database clustered with Patroni, and enabled cache mode ispn so sessions replicate across nodes. TCP ports 7800 and 57800 were opened between the VMs for Infinispan communication and failure detection.
Each node registers its address in the JGROUPS_PING table at startup, allowing dynamic membership without static TCPPING lists. The JVM flag -Djgroups.external_addr and explicit node-name entries in cache-ispn.xml ensured correct visibility of external IPs and hostnames across data centers.
Failover tests included node restarts, database connectivity loss, and complete data-center isolation. When only Keycloak nodes lost connectivity while the database remained reachable, the cluster recovered automatically. Full data-center outages, however, produced split-brain states, multiple coordinators, and persistent 5xx errors. The built-in healthcheck did not detect the condition even after an upgrade that added cluster-specific checks.
A temporary Python watcher was deployed beside each container. It polled health endpoints and the JGROUPS_PING table, restarting any node that appeared as an extra coordinator. The root cause was reported in GitHub issue 45980; Keycloak developers acknowledged the bug and shipped a fix. After verification on test and staging environments, the production cluster was updated and now tolerates single data-center failure without session loss.
Related articles
GreyNoise Detects Active Exploitation Attempts of CVE-2021-36260 Against Hikvision Cameras
GreyNoise recorded exploitation attempts targeting CVE-2021-36260 in Hikvision cameras and recorders between September 21 and October 1. The vulnerability carries a CVSS score of 9.8 and allows unauthenticated remote command execution through insufficient input validation in the embedded web server. Attack traffic originated from four IP addresses, three routed through a commercial VPN in Lithuania and one from a Ukrainian residential network, with all targets located in Ukraine. Attackers leveraged a publicly available Nuclei template to probe devices, though GreyNoise confirmed only scanning activity and not successful compromises. The five-year-old flaw remains actively scanned despite an available firmware patch from Hikvision and a CISA advisory recommending immediate updates. Password changes provide no protection because the attack requires no authentication. Defenders are advised to apply firmware updates, remove devices from public internet exposure, and segment video surveillance networks from critical infrastructure.
Splunk Enterprise Discloses 46 Vulnerabilities Including Critical Patroni Authentication Flaw
Splunk has published three security advisories detailing a total of 46 vulnerabilities affecting Splunk Enterprise and related components. Three of the issues were rated critical, with CVE-2026-76268 receiving a CVSS v3.1 base score of 9.8. The flaw resides in the Patroni REST API used for PostgreSQL cluster management within search head clusters, allowing unauthenticated remote attackers to execute arbitrary operating system commands. Another high-severity issue, CVE-2026-76266, enables local privilege escalation to root on Linux systems during package updates. The remaining vulnerabilities cover product code, internally identified problems, and third-party packages. Organizations are urged to apply the available patches promptly.
Smart Fish Tank Power Strip Server Breached, Killing Aquarium Fish During National Day Holiday
During China's National Day holiday, the cloud servers of Woda Technology's smart power strips for fish tanks were compromised by malicious hackers, causing widespread remote disconnections and power outages for user devices. The attack left heating rods, oxygen pumps, and circulation systems offline for hours, resulting in the deaths of koi, arowana, and other ornamental fish that users had maintained for years. Woda issued a public notice confirming the intrusion was not a product defect or user error but a deliberate network attack, and the company has since upgraded firewalls, added multi-layer cloud protections, deployed backup servers, and improved local offline logic to prevent future failures. The incident highlights a critical IoT design flaw where devices rely entirely on vendor cloud platforms for control, allowing attackers who breach the server to remotely manage household appliances at scale. Security experts note that the same architecture is used across smart speakers, locks, cameras, and other consumer devices, creating a broad attack surface with minimal updates or segmentation. Woda has reported the case to authorities and preserved logs for forensic investigation.
CISA Adds Five Actively Exploited Vulnerabilities in Apache Struts, BIND, ProFTPD, Strapi and ONLYOFFICE Docs to KEV Catalog
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added five vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog on October 8, 2026, confirming active exploitation in the wild. The affected products include Apache Struts, BIND, ProFTPD, Strapi, and ONLYOFFICE Docs, with CVEs issued between 2015 and 2023. Federal agencies have until October 11, 2026, to apply mitigations or remove affected systems. One highlighted issue, Strapi CVE-2023-22894, stems from plaintext storage of sensitive information, allowing authenticated attackers to extract user data via query filters. When combined with CVE-2023-22621, the flaws enable remote code execution. CISA also warned that some impacted products may no longer receive vendor support.