What is the CVSS score of EUVD-2026-52231?

EUVD-2026-52231 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.4%.

Which versions of Unisoc Modem are affected by EUVD-2026-52231?

A critical remote denial-of-service vulnerability in Unisoc modem chipsets (T8100, T9100, T8200, T8300) allows attackers to remotely disable cellular connectivity on affected devices without…

How to fix or mitigate EUVD-2026-52231?

Within 24 hours, conduct a comprehensive asset inventory to identify all devices using affected Unisoc chipsets (T8100, T9100, T8200, T8300) and contact Unisoc directly for patch availability timelines and interim technical guidance. Over the next 7 days, implement network-level defenses including rate limiting and filtering on cellular interfaces, deploy monitoring and alerting for unexpected modem resets or connectivity failures, and establish incident response procedures for cellular outage scenarios. Within 30 days, coordinate with Unisoc on patching schedules, evaluate architectural alternatives such as multi-carrier redundancy for critical systems, and conduct testing of failover procedures to alternative connectivity methods.

Unisoc Modem EUVD-2026-52231

| CVE-2026-21550 HIGH

Improper Input Validation (CWE-20)

2026-08-03 Unisoc

GHSA-r872-7phc-hmjf

Denial Of Service T8100 T9100 T8200 T8300 Unisoc Shanghai Technologies Co Ltd

7.5

CVSS 3.1 · Vendor: Unisoc

Severity by source

Vendor (Unisoc) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

vuln.today AI

7.5 HIGH

Modem receives network-layer input without authentication or interaction required; impact is solely availability loss with no confidentiality or integrity effect.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (Unisoc).

CVSS VectorVendor: Unisoc

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Aug 03, 2026 - 08:24 vuln.today

CVE Published

Aug 03, 2026 - 07:18 cve.org

HIGH 7.5

DescriptionCVE.org

In modem, there is a possible improper input validation. This could lead to remote denial of service with no additional execution privileges needed

AnalysisAI

Remote denial of service in the Unisoc modem component of T8100, T9100, T8200, and T8300 chipsets allows unauthenticated network-adjacent or remote attackers to crash the modem by sending malformed input, severing cellular connectivity on affected devices. The CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H vector confirms no privileges or user interaction are required, and the attack surface is the baseband network interface. No public exploit has been identified at time of analysis, and this vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Technical ContextAI

The vulnerability resides in the modem firmware of Unisoc chipset families T8100, T9100, T8200, and T8300, as identified by the CPE cpe:2.3:a:unisoc_(shanghai)_technologies_co.,_ltd.:t8100/t9100/t8200/t8300. Unisoc (formerly Spreadtrum Communications) is a Chinese semiconductor company producing SoCs primarily for budget and mid-range Android smartphones, with significant market presence in emerging markets. The modem component handles the cellular protocol stack - including LTE and potentially NR (5G) baseband processing - and is responsible for parsing network-layer signaling data. Although no CWE is formally assigned, the vendor description explicitly names improper input validation as the root cause class, meaning the modem processes externally supplied data without sufficient type, bounds, or format checking, causing a crash or unresponsive state when malformed input is received.

RemediationAI

The primary remediation is to apply the modem firmware patch distributed via Unisoc's security bulletin at https://www.unisoc.com/en/support/product-security-bulletin/2084109408382668801. OEMs (device manufacturers) using T8100, T9100, T8200, or T8300 chipsets must integrate the patched modem firmware into Android security update packages and push updates to end users; end users should apply available OEM security updates promptly. No exact patched firmware version number is independently confirmed from the available data - OEMs should contact Unisoc directly for the specific patched binary. As a compensating control where patching is not yet available, restricting device use to trusted cellular networks and avoiding unknown or rogue base stations may reduce exposure, though this does not eliminate the vulnerability and has significant operational impact on device usability.