CVE-2026-31780: Linux kernel · wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 11 Nov 2026, 22:20 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
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
- git.kernel.org/stable/c/34a23fd9ddd683a03c7e8cc0ceded3e59e354b99 (opens in a new tab)
- git.kernel.org/stable/c/549f02d8ec94d39092ab6d9b103d0d6783a4b024 (opens in a new tab)
- git.kernel.org/stable/c/bfbddeadd4779651403035ee177ae2f22f9f5521 (opens in a new tab)
- git.kernel.org/stable/c/9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7 (opens in a new tab)
- git.kernel.org/stable/c/c97b2a00059608592ad0d86fbb813a4f8cf9464b (opens in a new tab)
- git.kernel.org/stable/c/d8388614de613c28eeb659c10115060a83739924 (opens in a new tab)
- git.kernel.org/stable/c/0c7f21d8bd2f93998b72b7a7f93152336aeca4dd (opens in a new tab)
- git.kernel.org/stable/c/d049e56b1739101d1c4d81deedb269c52a8dbba0 (opens in a new tab)