CVE-2026-31780

high

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation The variable valuesize is declared as u8 but accumulates the total length of all SSIDs to scan. Each SSID contributes up to 33 bytes (IEEE80211_MAX_SSID_LEN + 1), and with WILC_MAX_NUM_PROBED_SSID (10) SSIDs the total can reach 330, which wraps around to 74 when stored in a u8. This causes kmalloc to allocate only 75 bytes while the subsequent memcpy writes up to 331 bytes into the buffer, resulting in a 256-byte heap buffer overflow. Widen valuesize from u8 to u32 to accommodate the full range.

References

https://git.kernel.org/stable/c/d8388614de613c28eeb659c10115060a83739924

https://git.kernel.org/stable/c/d049e56b1739101d1c4d81deedb269c52a8dbba0

https://git.kernel.org/stable/c/c97b2a00059608592ad0d86fbb813a4f8cf9464b

https://git.kernel.org/stable/c/bfbddeadd4779651403035ee177ae2f22f9f5521

https://git.kernel.org/stable/c/9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7

https://git.kernel.org/stable/c/549f02d8ec94d39092ab6d9b103d0d6783a4b024

https://git.kernel.org/stable/c/34a23fd9ddd683a03c7e8cc0ceded3e59e354b99

https://git.kernel.org/stable/c/0c7f21d8bd2f93998b72b7a7f93152336aeca4dd

Details

Source: Mitre, NVD

Published: 2026-05-01

Updated: 2026-05-01

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 8.4

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.0003