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PatchSiren cyber security CVE debrief

CVE-2026-20431 MediaTek, Inc. CVE debrief

A logic error in the Modem component of Mediatek products could lead to a possible system crash and remote denial of service. This issue has been assigned a CVSS score of 6.5 and a severity of MEDIUM. The vulnerability requires no user interaction and can be exploited remotely if a UE has connected to a rogue base station controlled by the attacker. The affected products and their configurations need to be assessed for potential exposure.

Vendor
MediaTek, Inc.
Product
MediaTek chipset
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-07
Original CVE updated
2026-07-24
Advisory published
2026-04-07
Advisory updated
2026-07-24

Who should care

Users of affected Mediatek products, specifically those using the Modem component, should be aware of this vulnerability and take necessary precautions to mitigate the risk. The affected operators, platforms, and security teams need to assess their exposure and implement compensating controls. Vulnerability management and security teams should prioritize patching or mitigating this vulnerability.

Technical summary

In Modem, there is a possible system crash due to a logic error. This could lead to remote denial of service, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. The vulnerability affects Mediatek products using the Modem component, and defenders should focus on securing these products.

Defensive priority

Medium priority, as the vulnerability requires no user interaction and can be exploited remotely.

Recommended defensive actions

  • Inventory and assess affected Mediatek products
  • Apply vendor-provided patches or updates
  • Implement compensating controls, such as monitoring for suspicious activity
  • Consider disabling Modem functionality if not required
  • Review and verify the affected scope and severity
  • Plan and track vendor-supported updates or mitigations
  • Monitor and detect potential exposure

Evidence notes

The CVE record was published on 2026-04-07T04:16:59.930Z and was last modified on 2026-07-24T22:10:00.140Z. The NVD entry is currently Analyzed. The evidence is limited, and defenders should verify the affected Mediatek products and their configurations. The logic error in Modem could lead to a possible system crash and remote denial of service. User interaction is not needed for exploitation.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-20431 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-20431

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-20431 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-20431

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.