In the modem OTA stack, there is a possible stack-based buffer overflow due to improper validation of scheduling information in SIB1 messages. This could lead to remote code execution or denial of service with no additional execution privileges needed.
Critical 9.8
CVE-2026-66086
Unisoc (Shanghai) Technologies Co., Ltd. Modem — remote code execution.
In the modem OTA stack, there is a possible stack-based buffer overflow due to improper validation of scheduling information in SIB1 messages.
WeaknessCWE-121: Stack buffer overflow
Published Updated Source NVD
CVSS 3.1
9.8
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit chance, 30 days
0.5%
Higher than 39% of all CVEs (EPSS)
Status
No known exploitation
Not in CISA KEV
Patch
Unknown
Check the vendor advisory
What happened
What to do
- 01Check whether you run Unisoc (Shanghai) Technologies Co., Ltd. Modem, and which version.
- 02Follow the vendor advisory for a fix or a workaround.
References
Timeline · UTC
- Published to NVD
- NVD record updated
Also actively exploited
Vendor
Unisoc (Shanghai) Technologies Co., Ltd.1 CVE in 30 days
All Unisoc (Shanghai) Technologies Co., Ltd. CVEs