Critical · published January 7, 2026
🚨 A sneaky flaw in the Undertow HTTP server could turn your app into a playground for attackers! 🔥 Think of it as a restaurant that doesn't check who made a reservation. If a diner can write their own name down, they could sit wherever they like, potentially causing chaos for everyone else! 🍽️ If left unchecked, attackers can poison your cache, perform internal scans, or even hijack user sessions. This could mean lost data, compromised accounts, and an absolute nightmare for recovery! 🔥
Think of it as a restaurant that doesn't check who made a reservation. If a diner can write their own name down, they could sit wherever they like, potentially causing chaos for everyone else! 🍽️ The flaw in Undertow involves improper validation of the Host header in HTTP requests, allowing malicious headers to slip through undetected, leading to various attacks.
If left unchecked, attackers can poison your cache, perform internal scans, or even hijack user sessions. This could mean lost data, compromised accounts, and an absolute nightmare for recovery! 🔥 Update Undertow to the latest version immediately to patch this issue. Review your server configurations for any additional security settings you can apply, and consider implementing strict validation for incoming headers. 🛡️ You've got this! Fixing this vulnerability will strengthen your defenses and keep your users safe! 💪✨
| Product | Versions | Fixed in |
|---|---|---|
| redhat/build_of_apache_camel | < 4.14.4 | 4.14.4 |
| redhat/data_grid | all versions | — |
| redhat/fuse | all versions | — |
| redhat/jboss_enterprise_application_platform | ≥ 8.0, < 8.0.12 | 8.0.12 |
| redhat/jboss_enterprise_application_platform | ≥ 8.1.0, < 8.1.3 | 8.1.3 |
| redhat/jboss_enterprise_application_platform | all versions | — |
| redhat/jboss_enterprise_application_platform | all versions | — |
| redhat/jboss_enterprise_application_platform_expansion_pack | all versions | — |
| redhat/process_automation | all versions | — |
| redhat/single_sign-on | all versions | — |
| redhat/undertow | < 2.2.39 | 2.2.39 |
| redhat/undertow | ≥ 2.3.0, < 2.3.21 | 2.3.21 |