CVE-2026-31675 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, network administrators, and security teams responsible for managing Linux-based systems, especially those using the net/sched: sch_netem component.

Why it matters

The CVE-2026-31675 vulnerability in the Linux kernel's net/sched: sch_netem component can lead to out-of-bounds memory access and potential denial-of-service attacks. Linux kernel developers, maintainers, and security teams should assess exposure and apply patches to prevent exploitation.

• Potential denial-of-service attacks through memory corruption
• Elevation of privileges through exploitation of the vulnerability
• Data tampering and corruption of network packets
• Verification of packet corruption logic to prevent bypassing security controls

Technical summary

The Linux kernel's net/sched: sch_netem component is vulnerable to an out-of-bounds memory access when packet corruption is enabled. The issue arises from the get_random_u32_below function being called with a zero argument, resulting in an unconstrained 32-bit random integer being used as an offset into the packet data. This can lead to potential memory corruption and denial-of-service attacks. The fix involves verifying that the packet head length is non-zero before attempting to corrupt the linear data area.

Defensive priority

High

Recommended defensive actions

• Review and apply the patches provided by the Linux kernel maintainers to ensure the vulnerability is fixed.
• Update Linux kernel to a version that includes the fix, such as applying commits a14b56863348686dd0387eea8ce66b85cf455908, 13a66ca1e235d4bcd53d12d4c68490cad7f8e46f, 3a2999704ac36cfb4041fed3652d26a3373e8d12, 4fd258e281fa8
• Monitor network traffic and system logs for potential exploitation attempts.
• Perform a thorough review of system configurations and network settings to identify potential vulnerabilities.
• Implement additional security controls, such as intrusion detection and prevention systems.
• Conduct regular security audits and vulnerability assessments to identify and address potential weaknesses.
• Review and update incident response plans to ensure preparedness in case of a security incident.

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, affected versions, and fixed versions. The Linux kernel maintainers have addressed the issue with multiple commits.

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.