CVE-2026-21928
📋 TL;DR
This vulnerability in Oracle Solaris 11 kernel allows unauthenticated attackers with network access via TCP to read sensitive system data. It affects Oracle Solaris 11 systems exposed to networks. The impact is limited to unauthorized data disclosure without system compromise.
💻 Affected Systems
- Oracle Solaris
📦 What is this software?
Solaris by Oracle
⚠️ Risk & Real-World Impact
Worst Case
Sensitive system information disclosure including configuration details, user data, or system state that could facilitate further attacks
Likely Case
Disclosure of non-critical system information that could aid reconnaissance for more serious attacks
If Mitigated
Limited impact with proper network segmentation and access controls preventing unauthorized TCP connections
🎯 Exploit Status
CVSS indicates low attack complexity and no authentication required via network
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Oracle Security Alert for specific patch
Vendor Advisory: https://www.oracle.com/security-alerts/cpujan2026.html
Restart Required: Yes
Instructions:
1. Review Oracle Security Alert CPJan2026 2. Download appropriate kernel patch 3. Apply patch following Oracle documentation 4. Reboot system
🔧 Temporary Workarounds
Network Access Control
allRestrict TCP access to Solaris systems using firewall rules
iptables -A INPUT -p tcp --dport [vulnerable-port] -j DROP
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="0.0.0.0/0" port port="[vulnerable-port]" protocol="tcp" reject'
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Solaris systems
- Deploy network-based intrusion detection to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check Solaris version: uname -a and verify if running Solaris 11 without patchCheck Version:
uname -a; pkg list entireVerify Fix Applied:
Verify patch installation via pkg list and check kernel version📡 Detection & Monitoring
Log Indicators:
- Unusual TCP connections to Solaris kernel ports
- Failed authentication attempts to kernel services
Network Indicators:
- Unexpected TCP traffic to Solaris systems on non-standard ports
- Network scans targeting Solaris services
SIEM Query:
source="solaris" AND (event_type="connection" OR event_type="access") AND dest_port=[vulnerable-port] AND src_ip NOT IN (trusted_ips)