CVE-2025-20756

System crash via undisclosed input-validation error

Published Dec 2, 2025 · Updated Dec 2, 2025

Improper input validation in MediaTek Modem NR15 allows physically proximate attackers to crash the system through a rogue base station. MediaTek identifies a logic error involving validation of a specified input type but has not published the affected modem routine, the invalid type, or the erroneous operation. Exploitation requires the UE to connect to an attacker-controlled base station; it needs no execution privileges or user interaction and only interrupts availability.

CVSS severity6.5
Medium
EPSS probability0.25%
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 MediaTek Modem NR15 allows physically proximate attackers to crash the system through a rogue base station. MediaTek identifies a logic error involving validation of a specified input type but has not published the affected modem routine, the invalid type, or the erroneous operation. Exploitation requires the UE to connect to an attacker-controlled base station; it needs no execution privileges or user interaction and only interrupts availability.

The record

CVE
CVE-2025-20756
Published
Dec 2, 2025
Updated
Dec 2, 2025
Vendor
MediaTek
Product
MediaTek Modem
Classifications
CWE-1287, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 2, 2025Record 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=Modem NR15

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

MediaTek · MediaTek Modemversion=Modem NR15

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:A/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1287Improper Validation of Specified Type of Input
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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