CVE-2026-2587
CRITICALCVE-2026-2587 is a critical-severity (CVSS 9.6) Expression Language Injection vulnerability in org.glassfish.main.admingui:admingui. O3 Security confirms whether CVE-2026-2587 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
GlassFish's gadget handler is vulnerable to RCE
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-2587.
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.
How urgent is this, really
CVE-2026-2587 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.glassfish.main.admingui:admingui☕org.glassfish.jsftemplating:jsftemplatingReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.glassfish.main.admingui:admingui | all versions | 8.0.2 |
| ☕Maven | org.glassfish.jsftemplating:jsftemplating | all versions | 4.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.glassfish.main.admingui:admingui. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.glassfish.main.admingui:admingui to 8.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-2587 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-2587 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
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 in your dependencies?
O3 detects CVE-2026-2587 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.