Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5 mt7996 mt7996_mcu_beacon_cntdwn buffer overflow

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.2	$5k-$25k	0.00

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5. The impacted element is the function mt7996_mcu_beacon_cntdwn of the component mt7996. The manipulation results in buffer overflow. This vulnerability was named CVE-2026-90366. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5. Affected is the function mt7996_mcu_beacon_cntdwn of the component mt7996. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: reserve space for the CSA-abort countdown TLV When a CSA countdown is active, mt7996_mcu_beacon_cntdwn() emits two bss_bcn_cntdwn_tlv entries (the CSA countdown and the CCA-abort BCC), but MT7996_BEACON_UPDATE_SIZE only reserved one. With MBSSID enabled and a near-maximum beacon template the extra 8 bytes could push the offload command past MT7996_MAX_BSS_OFFLOAD_SIZE and trigger skb_over_panic(). Reserve room for both countdown TLVs.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-90366 since 09/11/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 09/17/2026).

Upgrading to version 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch 1d348f96623ec20d700af7d4dfc00a74da6238ac/bc1d694a1ffe0062c3adf0db1d64ad54454398ec/45d8896e4cffffb2c6554ccbec6efe7a0d53166f/1a51aff0e048dc5b8252d65808b79939c942d6ec/50c66bab321140c49aa2ed779a3ec9d2f085b458 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.156
• 6.12.109
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 6.18.51
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
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CPE 2.2info

• 🔒
• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: 1d348f96623ec20d700af7d4dfc00a74da6238ac/bc1d694a1ffe0062c3adf0db1d64ad54454398ec/45d8896e4cffffb2c6554ccbec6efe7a0d53166f/1a51aff0e048dc5b8252d65808b79939c942d6ec/50c66bab321140c49aa2ed779a3ec9d2f085b458

Timelineinfo

09/11/2026 CVE reserved
09/17/2026 +6 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90366 (🔒)
GCVE (CVE): GCVE-0-2026-90366
GCVE (VulDB): GCVE-100-406908

Entryinfo

Created: 09/17/2026 21:56
Changes: 09/17/2026 21:56 (59)
Complete: 🔍
Cache ID: 216::103

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Discussion

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