CVE-2026-44890 netty CVE debrief

Who should care

Network administrators and security teams responsible for managing Netty deployments should assess their exposure to this vulnerability. This includes teams that use Netty in their applications, especially those using netty-codec-redis. Immediate action is necessary to prevent potential DoS attacks.

Why it matters

CVE-2026-44890 is a high-severity vulnerability in Netty's netty-codec-redis component, allowing for DoS attacks. Defenders should prioritize patching to prevent service disruption and potential OutOfDirectMemoryError. Network administrators and security teams managing Netty deployments must assess exposure and apply patches promptly.

• DoS attacks can lead to service unavailability, impacting business operations.
• Successful exploitation can cause OutOfDirectMemoryError, disrupting legitimate connections.
• Defenders need to verify their Netty versions and patch vulnerable installations promptly.
• Exposure assessment and patching are critical to prevent potential attacks.

Technical summary

The netty-codec-redis component in Netty is vulnerable to a DoS attack. An attacker can send crafted Redis payloads across multiple connections without `r n`, causing the server's direct memory pool to be exhausted (OutOfDirectMemoryError). This prevents legitimate connections from being processed. The issue is patched in versions 4.1.135.Final and 4.2.15.Final. Defenders should prioritize patching vulnerable Netty installations to prevent potential DoS attacks. This involves updating netty-codec-redis to versions 4.1.135.Final or 4.2.15.Final, or later. Network administrators and security teams responsible for managing Netty deployments should assess their exposure and apply patches as soon as possible.

Defensive priority

Defenders should prioritize patching vulnerable Netty installations to prevent potential DoS attacks. This involves updating netty-codec-redis to versions 4.1.135.Final or 4.2.15.Final, or later. Network administrators and security teams responsible for managing Netty deployments should assess their exposure and apply patches as soon as possible.

Recommended defensive actions

• Patch vulnerable Netty installations to versions 4.1.135.Final or 4.2.15.Final, or later.
• Assess exposure and apply patches as soon as possible.
• Monitor for potential DoS attacks targeting Netty deployments.
• 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 record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected versions. Vendor advisories and release notes confirm the patches in versions 4.1.135.Final and 4.2.15.Final.

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.