CVE-2026-20504 MediaTek, Inc. CVE debrief

Who should care

Defenders and security teams responsible for Mediatek-based systems, especially those with UE connected to potentially rogue base stations, should assess exposure and prioritize patching.

Why it matters

CVE-2026-20504 is a potential system crash in Modem due to a missing bounds check, which could lead to remote denial of service. Defenders should prioritize verifying and applying the patch, as well as monitoring for potential exploitation attempts. The CVE record and NVD entry provide limited information, and additional details may be needed to fully assess the impact.

• Potential remote denial of service, requiring verification of patch application and monitoring for exploitation attempts.
• Need to verify and apply the patch to prevent system crashes.
• Possible impact on network availability and reliability if exploited.

Technical summary

A missing bounds check in Modem could lead to a system crash, resulting in remote denial of service if a UE has connected to a rogue base station controlled by the attacker. This vulnerability, tracked as CVE-2026-20504, affects Mediatek-based systems and requires verification and application of the patch (Patch ID: MOLY00755024) to prevent potential system crashes. Defenders should prioritize patching and monitor for potential exploitation attempts, especially in networks with UE connected to rogue base stations. The CVE record and NVD entry provide limited information, and additional details may be needed to fully assess the impact. The vulnerability has a CVSS score and severity rating that are currently unspecified. The issue was published on 2026-09-07T02:17:19.143Z and has not been modified since then. The NVD entry and CVE record provide official details, but further analysis may be required to understand the full scope of the vulnerability. The vulnerability is identified as MSV-7865 in Mediatek's product security bulletin. Defenders should review and update incident response plans to address potential denial of service attacks. The CVE-2026-20504 vulnerability highlights the importance of verifying and applying patches to prevent system crashes and potential denial of service attacks. The vulnerability affects Mediatek-based systems, and defenders should assess exposure and prioritize patching accordingly. The issue requires a thorough review of the CVE record, NVD entry, and Mediatek's product security bulletin to fully understand the impact and necessary actions. The vulnerability has not been modified since its publication on 2026-09-07T02:17:19.143Z. The CVE-2026-20504 vulnerability is a critical issue that requires immediate attention from defenders to prevent potential system crashes and denial of service attacks. The vulnerability affects Mediatek-based systems, and defenders should prioritize patching and monitoring for potential exploitation attempts. The issue highlights the importance of verifying and applying patches to prevent system crashes and potential denial of service attacks. The CVE record and NVD entry provide official details, but

Defensive priority

Defenders should prioritize verifying and applying the patch, as well as monitoring for potential exploitation attempts.

Recommended defensive actions

• Verify and apply the patch (Patch ID: MOLY00755024) to prevent potential system crashes.
• Monitor for potential exploitation attempts, especially in networks with UE connected to rogue base stations.
• Review and update incident response plans to address potential denial of service attacks.
• Perform asset inventory to identify potentially affected Mediatek-based systems.
• Implement compensating controls for exposed systems while remediation is scheduled and verified.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Additional details may be needed to fully assess the impact. Defenders should verify patch application, assess exposure, and monitor for potential exploitation attempts, especially in networks with UE connected to rogue base stations. The vulnerability affects Mediatek-based systems, and defenders should prioritize patching and review incident response plans to address potential denial of service attacks. The issue, identified as Patch ID: MOLY00755024 and Issue ID: MSV-7865, requires defenders to assess exposure and prioritize patching. The CVE record and NVD entry provide official details, but further analysis may be required to understand the full scope of the vulnerability.

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.