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.
Published: 2026-10-12
Score: 8.3 High
EPSS: n/a
KEV: No
Impact: Remote Code Execution
Action: Apply Patch
AI Analysis

Impact

The vulnerability is a stack-based buffer overflow in the modem’s OTA stack caused by insufficient validation of scheduling information in SIB1 messages. Exploitation could permit an attacker to execute arbitrary code or crash the modem, and the attack does not require elevated privileges. This weakness is identified as CWE‑121 and carries a CVSS score of 8.3.

Affected Systems

The affected product is the modem firmware provided by Unisoc (Shanghai) Technologies Co., Ltd. No specific firmware version ranges are supplied, so all current releases should be considered vulnerable until a vendor statement clarifies otherwise.

Risk and Exploitability

The CVSS base score indicates a high severity, and while the EPSS score is unavailable the risk remains significant. The modem is reachable via OTA channels, making remote exploitation feasible. The vulnerability is not listed in the CISA KEV catalog, but the potential impact warrants prompt attention.

Generated by OpenCVE AI on October 12, 2026 at 03:22 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest vendor firmware or patch addressing the buffer overflow
  • If immediate firmware updates are unavailable, disable OTA updates or restrict SIB1 message processing
  • Monitor inbound traffic for anomalous SIB1 message patterns and implement rate limiting or filtering

Generated by OpenCVE AI on October 12, 2026 at 03:22 UTC.

Tracking

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Advisories

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History

Mon, 12 Oct 2026 02:15:00 +0000

Type Values Removed Values Added
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.
Title Stack-based Buffer Overflow in Modem
Weaknesses CWE-121
References
Metrics cvssV3_1

{'score': 8.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: Unisoc

Published:

Updated: 2026-10-12T01:28:35.334Z

Reserved: 2026-07-24T02:05:12.603Z

Link: CVE-2026-66086

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-12T02:16:57.600

Modified: 2026-10-12T02:16:57.600

Link: CVE-2026-66086

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-12T03:30:04Z

Weaknesses
  • CWE-121

    Stack-based Buffer Overflow