SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-66086

In the modem OTA stack, there is a possible stack-based buffer overflow due to improper validation of scheduling information in SIB1 messages.

CRITICAL 9.8EPSS 0.46%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.46% probability · 39th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-121
Source
security@unisoc.com
EPSS trend
0%3%5%12 October 2026: 0.46%26 October 2026: 0.46%12 October 202626 October 2026

EPSS moved from 0.5% on 12 October 2026 to 0.5% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.