What is CVE-2026-21003?

CVE-2026-21003 is a medium-severity vulnerability in Samsung Android, classified under CWE-20: IMPROPER INPUT VALIDATION. CVSS score: 6.8/10. Published 2026-04-13.

How severe is CVE-2026-21003?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Is CVE-2026-21003 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Samsung Android

CVE-2026-21003

Improper input validation in data related to network restrictions prior to SMR Apr-2026 Release 1 allows physical attackers to bypass the restrictions.

EPSS: 0.002 (5.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Samsung Android — versions 14.0, 15.0, 16.0
Samsung Mobile Devices — versions SMR Apr-2026 Release in Selected Android 14, 15, 16 devices

Public proof-of-concept exploits

George0Papasotiriou/CVE-2026-21003-JWT-none-Algorithm-Bypass-via-kid-Header-Omission

References

mobile.security@samsung.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-21003?: CVE-2026-21003 is a medium-severity vulnerability in Samsung Android, classified under CWE-20: IMPROPER INPUT VALIDATION. CVSS score: 6.8/10. Published 2026-04-13.
How severe is CVE-2026-21003?: Medium severity. CVSS v3 base score is 6.8 out of 10.
Is CVE-2026-21003 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.