CVE-2025-20704

Remote privilege escalation via unchecked modem input

Published Sep 1, 2025 · Updated Feb 26, 2026

Out-of-bounds write in MediaTek Modem NR17 and NR17R allows remote attackers to gain elevated privileges through a rogue base station. An undisclosed modem routine writes beyond its intended buffer because it processes attacker-controlled base-station input without a required bounds check. Exploitation requires a device user to connect the UE to an attacker-controlled base station; no prior execution privileges are required.

CVSS severity8.8
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in MediaTek Modem NR17 and NR17R allows remote attackers to gain elevated privileges through a rogue base station. An undisclosed modem routine writes beyond its intended buffer because it processes attacker-controlled base-station input without a required bounds check. Exploitation requires a device user to connect the UE to an attacker-controlled base station; no prior execution privileges are required.

The record

CVE
CVE-2025-20704
Published
Sep 1, 2025
Updated
Feb 26, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.0CISA CoordinatorCVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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