CVE-2026-21555Network attack vector

Unauthenticated modem service interruption

Published Aug 3, 2026 · Updated Aug 3, 2026

Improper input validation in the UNISOC UDX710 Yocto modem allows remote attackers to interrupt modem service via network input. UNISOC has not disclosed the validation locus, the input field accepted incorrectly, or whether the interruption is a crash, hang, or modem restart. No authentication, prior privileges, or user interaction is required; the reported consequence is limited to modem availability.

CVSS severity7.5
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in the UNISOC UDX710 Yocto modem allows remote attackers to interrupt modem service via network input. UNISOC has not disclosed the validation locus, the input field accepted incorrectly, or whether the interruption is a crash, hang, or modem restart. No authentication, prior privileges, or user interaction is required; the reported consequence is limited to modem availability.

The record

CVE
CVE-2026-21555
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
UNISOC
Product
UDX710
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Yocto

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

UNISOC · UDX710version=Yocto

Published CVSS scores

7.5UNISOCCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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