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CVE-2026-31780 Not scored

wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation

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.

Exploit probability 0.1%
Published May 1, 2026
Required by Not available
Last source change July 22, 2026

02 / AFFECTED SOFTWARE

Affected packages

Unknown Unknown
Linux Kernel

03 / CONNECTIONS

Connected vulnerabilities

04 / EVIDENCE

Source records

Open Source Vulnerabilities CVE-2026-31780

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.

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05 / REFERENCES

Further evidence