CVE-2026-21553 Denial of service in T8100/T9100/T8200/T8300
Remote attackers can cause denial of service in Unisoc Android devices via improper input validation in the modem component.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-21553?
CVE-2026-21553 is a high-severity denial of service vulnerability in Unisoc (Shanghai) Technologies Co., Ltd. T8100/T9100/T8200/T8300, published on 3 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In modem, there is a possible improper input validation. This could lead to remote denial of service with no additional execution privileges needed
Weakness: CWE-20
Which versions are affected by CVE-2026-21553?
How do I fix CVE-2026-21553?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-21553 being exploited?
There is no known exploitation of CVE-2026-21553 in the wild and no public exploit code.
Sources
Also known as A-517371324, ASB-A-517371324, GHSA-m8m7-6fxv-m3w9, U-3379457.