CVE-2026-93566 Red Hat CVE debrief

Who should care

Defenders responsible for Red Hat products, particularly those using Netty's netty-codec-http component, should assess exposure and prioritize mitigation. This includes administrators of Red Hat build of Quarkus, Red Hat AMQ Broker, Red Hat AMQ Clients, and other affected products.

Why it matters

CVE-2026-93566 is a medium-severity vulnerability in Netty's netty-codec-http component, allowing for HTTP request smuggling. Defenders should prioritize patching affected Red Hat products and implement strict HTTP request validation to mitigate potential information disclosure and unauthorized actions.

• Potential information disclosure due to HTTP request smuggling.
• Possible unauthorized actions through injected HTTP requests.
• Need for verification of affected versions and exposure.
• Priority for patching or mitigating vulnerable Red Hat products.

Technical summary

CVE-2026-93566 is a vulnerability in the netty-codec-http component of Netty, allowing for HTTP request smuggling due to improper handling of control characters in the chunk-size line. This can lead to unauthorized actions and potential information disclosure. Affected products include various Red Hat offerings such as Red Hat build of Quarkus, Red Hat AMQ Broker, and Red Hat AMQ Clients. Defenders should prioritize patching or mitigating this vulnerability, especially in environments where untrusted HTTP requests are processed. The vulnerability has a medium severity with a CVSS score of 6.5.

Defensive priority

Defenders should prioritize patching or mitigating this vulnerability, especially in environments where untrusted HTTP requests are processed.

Recommended defensive actions

• Patch or update affected Netty and Red Hat products according to vendor advisories.
• Implement strict validation of HTTP requests to mitigate potential smuggling attempts.
• Monitor for and respond to potential unauthorized actions or information disclosure.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE Program and NVD provide official records of this vulnerability. Red Hat has released advisories RHSA-2026:69440 and RHSA-2026:69470, detailing affected products and patches. Affected vendors and users should verify exposure and apply patches or mitigations according to vendor guidance. Official records indicate CVE-2026-93566 affects Netty's netty-codec-http component, allowing for HTTP request smuggling due to improper handling of control characters in the chunk-size line. Defenders should review official advisories and CVE

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.