CVE-2026-46340 netty CVE debrief

Who should care

Defenders responsible for Netty-based systems should assess exposure and prioritize patching vulnerable versions to prevent potential DoS attacks. This includes operators, platform administrators, vulnerability management teams, and security teams. They should review the official advisory and CVE record to validate affected scope, severity, and vendor guidance. Defenders should also monitor systems for potential performance degradation or increased memory

Why it matters

Defenders should prioritize patching vulnerable Netty versions to prevent potential DoS attacks and system performance degradation.

• Denial-of-service (DoS) attacks
• Increased memory usage and potential performance degradation
• Potential system crashes or instability

Technical summary

The vulnerability in Netty's netty-transport-sctp component can cause the accumulator to grow indefinitely, leading to increased memory usage and potential performance degradation. This can be exploited by an attacker to launch a DoS attack. The issue arises from the improper handling of SctpMessage fragments. Defenders should prioritize patching vulnerable Netty versions to prevent potential DoS attacks and system performance degradation. The vulnerability has been patched in Netty versions 4.1.135.Final and 4.2.15.Final.

Defensive priority

Defenders should prioritize patching vulnerable Netty versions to prevent potential DoS attacks.

Recommended defensive actions

• Patch vulnerable Netty versions (4.1.135.Final and 4.2.15.Final) to prevent potential DoS attacks
• Review and update affected systems to ensure they are running a patched version of Netty
• Monitor systems for potential performance degradation or increased memory usage
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• 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

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected versions. The Netty project has released patches for this vulnerability in versions 4.1.135.Final and 4.2.15.Final. Defenders should review the official advisory and CVE record to validate affected scope, severity, and vendor guidance. Evidence is limited to public sources and may not be comprehensive. Further verification is needed to confirm affected deployments and assess potential impact.

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.