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CVE-2025-21042 Samsung CVE debrief

CVE-2025-21042 is a Samsung Mobile Devices out-of-bounds write vulnerability that CISA added to the Known Exploited Vulnerabilities catalog on 2025-11-10. The KEV listing means CISA has identified it as a vulnerability with known exploitation, so it should be treated as a high-priority remediation item. The supplied corpus does not include a CVSS score or deeper technical detail, so defenders should rely on the vendor guidance referenced by CISA and patch or mitigate Samsung mobile devices as quickly as possible.

Vendor
Samsung
Product
Mobile Devices
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2025-11-10
Original CVE updated
2025-11-10
Advisory published
2025-11-10
Advisory updated
2025-11-10

Who should care

Organizations that manage Samsung mobile devices, especially endpoint and mobile device management teams, enterprise security teams, and users responsible for timely device updates. Federal agencies and other environments that follow CISA KEV guidance should treat this as especially urgent.

Technical summary

The available source corpus identifies CVE-2025-21042 as an out-of-bounds write issue affecting Samsung Mobile Devices. CISA lists it in the Known Exploited Vulnerabilities catalog with a date added of 2025-11-10 and a due date of 2025-12-01. No CVSS score, attack vector, or component-level exploit detail is provided in the supplied data. The key defensive implication is that the vulnerability is known to be exploited and should be remediated using vendor guidance and available updates.

Defensive priority

High. Any CISA KEV entry with known exploitation should be prioritized ahead of routine maintenance, and this item has a remediation due date of 2025-12-01 in the supplied KEV record.

Recommended defensive actions

  • Apply Samsung's mitigation or update guidance referenced by CISA as soon as possible.
  • Review the Samsung security update reference cited in the KEV metadata for April 2025 and determine which device models or firmware branches are affected.
  • Prioritize patching or mitigation in mobile device management queues before non-KEV issues.
  • If mitigations are unavailable, follow CISA KEV guidance and consider discontinuing use of the affected product until a fix is available.
  • For applicable federal or cloud-managed environments, align remediation timing with BOD 22-01 requirements and internal emergency patching procedures.
  • Verify fleet coverage and confirm that affected Samsung devices have received the required update or workaround.

Evidence notes

Evidence is limited to the supplied CISA KEV record and official references. The corpus states vendorProject=Samsung, product=Mobile Devices, vulnerabilityName='Samsung Mobile Devices Out-of-Bounds Write Vulnerability,' dateAdded=2025-11-10, dueDate=2025-12-01, and knownRansomwareCampaignUse=Unknown. The KEV metadata also cites the Samsung security update URL and the NVD detail page for CVE-2025-21042, but no additional technical exploitation details were included in the supplied material.

Official resources

CISA KEV entry published and modified on 2025-11-10 in the supplied corpus. No separate vendor advisory publication date was provided in the source corpus beyond the Samsung security update reference included in CISA metadata.