CVE-2026-12606 Eclipse Foundation CVE debrief

Who should care

Users of Eclipse Grizzly versions before 5.0.2 should be aware of this vulnerability and take steps to mitigate it. This includes operators, platform administrators, vulnerability management teams, and security teams who need to assess the impact on their systems and plan for mitigation.

Technical summary

Eclipse Grizzly in versions before 5.0.2, cannot properly parse the trailer section in malformed trailer header's line, which can be leveraged to perform HTTP request smuggling. The CVSS score for this vulnerability is 6.3, with a severity rating of MEDIUM. This issue is specific to the parsing of trailer sections in HTTP requests.

Defensive priority

Medium priority should be given to patching or mitigating this vulnerability, as it could potentially be used to perform HTTP request smuggling attacks.

Recommended defensive actions

• Inventory and check systems using Eclipse Grizzly versions before 5.0.2
• Apply the patch or upgrade to Eclipse Grizzly version 5.0.2 or later
• Monitor for potential HTTP request smuggling attacks
• Consider implementing compensating controls, such as web application firewalls
• Review and verify system configurations for exposure

Evidence notes

The CVE record was published on 2026-07-14T09:16:39.920Z and has not been modified since then. The NVD entry is currently 6.3 (MEDIUM). The Eclipse Grizzly vulnerability affects users of versions before 5.0.2. Evidence is limited to CVE and NVD details. Defenders should verify system configurations and review vendor advisories for patching guidance.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.