CVE-2026-12630 zephyrproject CVE debrief

Who should care

Users of the Zephyr operating system who have enabled 6LoWPAN IP Header Compression are advised to take action. This includes operators, platform administrators, vulnerability management teams, and security teams who need to assess the impact of this vulnerability on their systems and implement necessary mitigations. The vulnerability can be exploited by an unauthenticated attacker on the radio/adjacent link, making it essential for those responsible for system security to review and apply patches or other mitigations as soon as possible. Additionally, users should review compensating controls for exposed systems while remediation is scheduled and verified, and monitor for suspicious activity that could indicate exploitation attempts. Asset inventory management is also crucial to identify potentially affected systems. Rolling back change windows and tracking exceptions can help manage the remediation process effectively. Source tracking should be implemented to verify the effectiveness of mitigations and detect potential security incidents related to this vulnerability. Monitoring relevant logs and detection systems can help identify potential security incidents related to this vulnerability. Implementing these measures can help minimize the risk associated with this out-of-bounds read vulnerability in Zephyr's 6LoWPAN IP Header Compression code. Users should also consider the potential operational impact of this vulnerability, including the possibility of denial-of-service attacks, and plan accordingly. The vulnerability's source-confidence limits and review context should be taken into account when prioritizing and implementing mitigations. Overall, a comprehensive approach to vulnerability management, including patching, monitoring, and compensating controls, is necessary to address this issue effectively. By taking these steps, users can help protect their systems from potential exploitation and minimize the risk of security incidents related to this vulnerability. Effective communication and coordination among teams, including operators, administrators, and security personnel, are essential to ensure a timely and effective response to this vulnerability. By

Technical summary

The vulnerability exists in the get_ihpc_inlined_size() function, which is used to uncompress IP headers in the 6LoWPAN protocol. The function uses an index built from the M, DAC, and DAM bits of the received IPHC dispatch word to look up the destination inline size in the da_inline_size_table. However, the reserved combinations 13, 14, and 15 are not bounds-checked, leading to an out-of-bounds read. This can cause a denial-of-service on the receiver.

Defensive priority

Medium priority due to potential for denial-of-service attacks

Recommended defensive actions

• Apply the patch from the Zephyr project
• Restrict access to the affected system
• Monitor for suspicious activity
• 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 vulnerability is caused by an out-of-bounds read in the get_ihpc_inlined_size() function, which is reached on every inbound 6LoWPAN frame. The function uses an index built from the M, DAC, and DAM bits of the received IPHC dispatch word to look up the destination inline size in the da_inline_size_table. However, the reserved combinations 13, 14, and 15 are not bounds-checked, leading to an out-of-bounds read.

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.