PatchTheCVEh2o vulnerabilities and fixes
Recent CVEs affecting h2o, with upgrade or downgrade steps. 1 tracked.
h2o has 1 tracked vulnerability, 1 critical. A fixed release or vendor patch exists for 1. Most recent: 2026-04-23. Highest priority: CVE-2026-3960 (score 59/100).
- CVE-2026-3960 CRITICAL 9.8 UPGRADE A critical remote code execution vulnerability exists in the unauthenticated REST API endpoint /99/ImportSQLTa
FAQ
How do I fix h2o vulnerabilities?
Open the CVE for your version, check the affected range, then follow the listed action: upgrade to the fixed release, or downgrade or mitigate if no fix exists yet. Commands for each OS are shown on every CVE page.
Is h2o being exploited right now?
None of the tracked h2o CVEs are on the CISA Known Exploited Vulnerabilities list at the moment. This is checked every 20 minutes.
Which h2o CVE should I patch first?
CVE-2026-3960 currently ranks highest (59/100): A critical remote code execution vulnerability exists in the unauthenticated REST API endpoint /99/ImportSQLTa.