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CVE-2026-21121 Samsung Mobile CVE debrief

CVE-2026-21121 Improper handling of insufficient permission in CmcCore prior to SMR Oct-2026 Release 1 allows local attackers to use the privileged APIs. This vulnerability affects Samsung Mobile Devices, specifically those running CmcCore prior to the October 2026 security update. The improper handling of insufficient permissions in CmcCore could allow local attackers to escalate privileges by using privileged APIs. Defenders responsible for Samsung Mobile Devices should assess exposure and prioritize applying the October 2026 security update to address CVE-2026-21121. The CVE Program and NVD records indicate that CVE-2026-21121 is related to improper handling of insufficient in

Vendor
Samsung Mobile
Product
Samsung Mobile Devices
CVSS
MEDIUM 6.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-12
Original CVE updated
2026-10-12
Advisory published
2026-10-12
Advisory updated
2026-10-12

Who should care

Defenders responsible for Samsung Mobile Devices should assess exposure and prioritize applying the October 2026 security update to address CVE-2026-21121.

Why it matters

CVE-2026-21121 requires defenders to prioritize verifying and applying the October 2026 security update for Samsung Mobile Devices to address improper handling of insufficient permissions in CmcCore, which could allow local attackers to use privileged APIs.

  • Local attackers may use privileged APIs to escalate privileges
  • Defenders must verify and apply the October 2026 security update
  • Inventory checks are necessary to ensure Samsung Mobile Devices are up-to-date

Technical summary

CVE-2026-21121 is related to improper handling of insufficient permissions in CmcCore prior to SMR Oct-2026 Release 1, allowing local attackers to use privileged APIs. This vulnerability affects Samsung Mobile Devices running CmcCore prior to the October 2026 security update. The improper handling of insufficient permissions in CmcCore could allow local attackers to escalate privileges. The CVE Program and NVD records indicate that CVE-2026-21121 is related to improper handling of insufficient permissions in CmcCore prior to SMR Oct-2026 Release 1. Samsung Mobile

Defensive priority

Defenders should prioritize verifying and applying the October 2026 security update for Samsung Mobile Devices to address the improper handling of insufficient permissions in CmcCore.

Recommended defensive actions

  • Verify and apply the October 2026 security update for Samsung Mobile Devices
  • Review and update inventory of Samsung Mobile Devices to ensure they are running SMR Oct-2026 Release 1 or later
  • Monitor for local attacks attempting to use privileged APIs

Evidence notes

The CVE Program and NVD records indicate that CVE-2026-21121 is related to improper handling of insufficient permissions in CmcCore prior to SMR Oct-2026 Release 1. Samsung Mobile Devices are affected.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-21121 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-21121

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

  • CVE-2026-21121 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-21121

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

Supplemental references

  • CVE-2026-21121

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/21xxx/CVE-2026-21121.json

    cve_program_cvelist_v5

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.