High 7.8Published May 1, 2026

CVE-2026-31780wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation

Updated under an hour ago (Oct 28, 2026, 10:30 PM ET)

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Exploited in the last 30 days

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.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Aug 5, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from c5c77ba18ea66aa05441c71e38473efb787705a4 before 34a23fd9ddd683a03c7e8cc0ceded3e59e354b99; from c5c77ba18ea66aa05441c71e38473efb787705a4 before 549f02d8ec94d39092ab6d9b103d0d6783a4b024; from c5c77ba18ea66aa05441c71e38473efb787705a4 before bfbddeadd4779651403035ee177ae2f22f9f5521; from c5c77ba18ea66aa05441c71e38473efb787705a4 before 9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7; from c5c77ba18ea66aa05441c71e38473efb787705a4 before c97b2a00059608592ad0d86fbb813a4f8cf9464b; from c5c77ba18ea66aa05441c71e38473efb787705a4 before d8388614de613c28eeb659c10115060a83739924; from c5c77ba18ea66aa05441c71e38473efb787705a4 before 0c7f21d8bd2f93998b72b7a7f93152336aeca4dd; from c5c77ba18ea66aa05441c71e38473efb787705a4 before d049e56b1739101d1c4d81deedb269c52a8dbba0	CNA record
linux linux_kernel linux:linux_kernel	from 4.2 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.134; from 6.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0; and 5 more ranges	NVD

References

References

https://git.kernel.org/stable/c/34a23fd9ddd683a03c7e8cc0ceded3e59e354b99	patch
https://git.kernel.org/stable/c/549f02d8ec94d39092ab6d9b103d0d6783a4b024	patch
https://git.kernel.org/stable/c/bfbddeadd4779651403035ee177ae2f22f9f5521	patch
https://git.kernel.org/stable/c/9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7	patch
https://git.kernel.org/stable/c/c97b2a00059608592ad0d86fbb813a4f8cf9464b	patch
https://git.kernel.org/stable/c/d8388614de613c28eeb659c10115060a83739924	patch
https://git.kernel.org/stable/c/0c7f21d8bd2f93998b72b7a7f93152336aeca4dd	patch
https://git.kernel.org/stable/c/d049e56b1739101d1c4d81deedb269c52a8dbba0	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.