SB20260918309 - Incorrect Calculation of Buffer Size in Linux kernel mt76 mt7996 driver

Description

This security bulletin contains information about 1 vulnerability.

1) Incorrect Calculation of Buffer Size (CVE-ID: CVE-2026-90366)

CWE-ID: CWE-131 - Incorrect Calculation of Buffer Size

CVSSv4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause a denial of service.

The vulnerability exists due to an incorrect buffer size calculation in the MT7996 beacon update size calculation when processing a beacon update while a CSA countdown is active. A local privileged user can trigger the emission of two bss_bcn_cntdwn_tlv entries to cause a denial of service.

Exploitation requires MBSSID to be enabled and a near-maximum beacon template.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1a51aff0e048dc5b8252d65808b79939c942d6ec
• https://git.kernel.org/stable/c/1d348f96623ec20d700af7d4dfc00a74da6238ac
• https://git.kernel.org/stable/c/45d8896e4cffffb2c6554ccbec6efe7a0d53166f
• https://git.kernel.org/stable/c/50c66bab321140c49aa2ed779a3ec9d2f085b458
• https://git.kernel.org/stable/c/bc1d694a1ffe0062c3adf0db1d64ad54454398ec