CVE-2026-20408

Adjacent privilege escalation via WLAN heap overwrite

Published Feb 2, 2026 · Updated Feb 2, 2026

Heap-based buffer overflow in MediaTek chipset WLAN code allows remote attackers to escalate privileges without user interaction. The WLAN component performs an out-of-bounds heap write, but MediaTek has not disclosed the affected routine, input field, or copy operation. An attacker must be within wireless range; successful exploitation grants elevated execution without prior privileges or user action.

CVSS severity8.8
High
EPSS probability0.28%
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 MediaTek chipset WLAN code allows remote attackers to escalate privileges without user interaction. The WLAN component performs an out-of-bounds heap write, but MediaTek has not disclosed the affected routine, input field, or copy operation. An attacker must be within wireless range; successful exploitation grants elevated execution without prior privileges or user action.

The record

CVE
CVE-2026-20408
Published
Feb 2, 2026
Updated
Feb 2, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, CWE-122, T1068
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 2, 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

8.8CISA-ADPCVSS:3.1/AV:A/AC:L/PR:N/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 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
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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