CVE-2026-20585 MediaTek, Inc. CVE debrief

Who should care

Defenders responsible for Mediatek-based systems, particularly those using affected Modem versions, should assess exposure and apply patches from the vendor. The vulnerability affects Mediatek-based systems, and defenders should prioritize verifying affected versions and applying patches. The CVE record was published on 2026-11-02T03:17:36.283Z and has not been modified since then.

Why it matters

CVE-2026-20585 is a possible out of bounds write due to a missing bounds check in Mediatek's Modem. Defenders should prioritize verifying affected versions and applying patches from the vendor.

• Remote escalation of privilege is possible if a UE has connected to a rogue base station controlled by the attacker.
• Defenders need to verify affected versions and apply patches from the vendor.

Technical summary

A possible out of bounds write due to a missing bounds check in Modem could lead to remote escalation of privilege if a UE has connected to a rogue base station controlled by the attacker. The vulnerability affects Mediatek-based systems, particularly those using affected Modem versions. Defenders should prioritize verifying affected versions and applying patches from the vendor. The CVE record was published on 2026-11-02T03:17:36.283Z and has not been modified since then. The vendor, Mediatek, has provided a patch ID: MOLY01338165.

Defensive priority

Defenders should prioritize verifying affected versions and applying patches from the vendor.

Recommended defensive actions

• Verify affected versions with the vendor
• Apply patches from the vendor
• 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
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance

Evidence notes

The CVE description notes a possible out of bounds write due to a missing bounds check in Modem. The vendor, Mediatek, has provided a patch ID: MOLY01338165. The vulnerability affects Mediatek-based systems, particularly those using affected Modem versions. Defenders should verify affected versions and apply patches from the vendor. The CVE record was published on 2026-11-02T03:17:36.283Z and has not been modified since then.

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.