CVE-2026-2587
CRITICALA critical Remote Code Execution (RCE) vulnerability was identified in the server-side template rendering mechanism used by the Glassfish gadget handler. The application processes .xml…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
A critical Remote Code Execution (RCE) vulnerability was identified in the server-side template rendering mechanism used by the Glassfish gadget handler. The application processes .xml files and evaluates user-supplied values within a context where Expression Language (EL) “expressions” are processed without proper sanitization or escaping. By injecting expressions such as #{7*7}, the server returns 49, confirming server-side EL evaluation. This issue allows a remote attacker to fully compromise the underlying host, enabling capabilities as reading/modifying data, executing arbitrary commands, persistence, and lateral movement. This issue affects Eclipse GlassFish: from 8.0.0 to 8.0.1, fixed in 8.0.2; 7.1.0, fixed in 7.1.1; from 7.0.0 to 7.0.25, fixed in 7.0.26. Impact on versions from 5.1.0 to 6.2.5 is unknown.
Affected Products
glassfisheclipseDetection & mitigation playbook
Vendor / applianceDetect
Inventory every eclipse glassfish deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the eclipse glassfish security patch or hotfix for CVE-2026-2587 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-2587 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-2587. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-2587 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-2587 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.