CVE-2026-31780
wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation
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.
INFO
Published Date :
May 1, 2026, 3:16 p.m.
Last Modified :
May 1, 2026, 3:24 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-31780
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to the fixed version.
- Widen the valuesize variable from u8 to u32.
- Ensure SSIDs are validated before processing.
- Review memory allocation and copy operations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-31780.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31780 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-31780
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-31780 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-31780 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 01, 2026
Action Type Old Value New Value Added 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. Added Reference https://git.kernel.org/stable/c/0c7f21d8bd2f93998b72b7a7f93152336aeca4dd Added Reference https://git.kernel.org/stable/c/34a23fd9ddd683a03c7e8cc0ceded3e59e354b99 Added Reference https://git.kernel.org/stable/c/549f02d8ec94d39092ab6d9b103d0d6783a4b024 Added Reference https://git.kernel.org/stable/c/9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7 Added Reference https://git.kernel.org/stable/c/bfbddeadd4779651403035ee177ae2f22f9f5521 Added Reference https://git.kernel.org/stable/c/c97b2a00059608592ad0d86fbb813a4f8cf9464b Added Reference https://git.kernel.org/stable/c/d049e56b1739101d1c4d81deedb269c52a8dbba0 Added Reference https://git.kernel.org/stable/c/d8388614de613c28eeb659c10115060a83739924