CVE-2025-20657

Local privilege escalation via vdec out-of-bounds write

Published Apr 7, 2025 · Updated Feb 26, 2026

An out-of-bounds write in MediaTek vdec on Android 12.0 and 15.0 allows local users with System privilege to escalate privileges. MediaTek attributes the permission bypass to improper input validation in vdec but does not disclose the specific input or erroneous write operation. Exploitation requires existing System privilege, needs no user interaction, and permits further local privilege escalation.

CVSS severity6.7
Medium
EPSS probability0.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in MediaTek vdec on Android 12.0 and 15.0 allows local users with System privilege to escalate privileges. MediaTek attributes the permission bypass to improper input validation in vdec but does not disclose the specific input or erroneous write operation. Exploitation requires existing System privilege, needs no user interaction, and permits further local privilege escalation.

The record

CVE
CVE-2025-20657
Published
Apr 7, 2025
Updated
Feb 26, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1404
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 7, 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 vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.7CISA-ADPCVSS:3.1/AV:L/AC:L/PR:H/UI:N/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.

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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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1404Exploitation for Privilege Escalation

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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