CVE-2025-20760

Denial of service via uncaught exception assertion

Published Jan 6, 2026 · Updated Jan 6, 2026

Reachable assertion in MediaTek Modem allows physically proximate attackers to interrupt modem service through a rogue base station. An uncaught exception causes modem code to read uninitialized heap data and reach an assertion rather than handle the exceptional state. Exploitation requires a device to connect to an attacker-controlled cellular base station; no privileges or user interaction are required, and the reported consequence is service interruption rather than data access or modification.

CVSS severity6.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in MediaTek Modem allows physically proximate attackers to interrupt modem service through a rogue base station. An uncaught exception causes modem code to read uninitialized heap data and reach an assertion rather than handle the exceptional state. Exploitation requires a device to connect to an attacker-controlled cellular base station; no privileges or user interaction are required, and the reported consequence is service interruption rather than data access or modification.

The record

CVE
CVE-2025-20760
Published
Jan 6, 2026
Updated
Jan 6, 2026
Vendor
MediaTek
Product
MediaTek Modem
Classifications
CWE-617, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 6, 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=Modem NR15, NR16, NR17

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

MediaTek · MediaTek Modemversion=Modem NR15, NR16, NR17

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-617Reachable Assertion
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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