CVE-2026-20465

Adjacent privilege escalation via unchecked heap write

Published Aug 3, 2026 · Updated Aug 3, 2026

Heap-based buffer overflow in the MediaTek chipset wlan AP driver allows remote attackers on an adjacent network to escalate privileges. The driver performs a heap write without a required bounds check; MediaTek has not disclosed the affected function or malformed input. Exploitation requires no existing privileges or user interaction; the affected chipset models are MT6890, MT7915, MT7916, MT7981, and MT7986.

CVSS severity8.1
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in the MediaTek chipset wlan AP driver allows remote attackers on an adjacent network to escalate privileges. The driver performs a heap write without a required bounds check; MediaTek has not disclosed the affected function or malformed input. Exploitation requires no existing privileges or user interaction; the affected chipset models are MT6890, MT7915, MT7916, MT7981, and MT7986.

The record

CVE
CVE-2026-20465
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
MediaTek
Product
MediaTek Chipset
Classifications
CWE-122, T1068
Attack vector
adjacent
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=MT6890
  2. Affected versionversion=MT7915
  3. Affected versionversion=MT7916
  4. Affected versionversion=MT7981
  5. Affected versionversion=MT7986

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

MediaTek · MediaTek Chipsetversion=MT6890; version=MT7915; version=MT7916; version=MT7981; version=MT7986

Published CVSS scores

8.1CISA-ADPCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

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 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-122Heap-based Buffer Overflow
T1068Exploitation 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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