CVE-2026-53250

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A Time-of-Check to Time-of-Use (TOCTOU) issue exists in the xsk skb metadata() function. The TX metadata area is located in the UMEM buffer, which is memory-mapped and can be written to by userspace concurrently. The function reads csum start and csum offset from shared memory for bounds validation and then reads them again for skb assignment. A malicious userspace application can overwrite these variables between the two reads, bypassing the bounds check and leading to out-of-bounds memory access during checksum computation in the transmit path.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.