CVE-2026-31614: Linux Kernel

High severity, CVSS 7.1. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix off-by-8 bounds check in check_wsl_eas() The bounds check uses (u8 *)ea + nlen + 1 + vlen as the end of the EA name and value, but ea_data sits at offset sizeof(struct smb2_file_full_ea_info) = 8 from ea, not at offset 0. The strncmp() later reads ea->ea_data[0..nlen-1] and the value bytes follow at ea_data[nlen+1..nlen+vlen], so the actual end is ea->ea_data + nlen + 1 + vlen. Isn't pointer math fun? The earlier check (u8 *)ea > end - sizeof(*ea) only guarantees the 8-byte header is in bounds, but since the last EA is placed within 8 bytes of the end of the response, the name and value bytes are read past the end of iov. Fix this mess all up by using ea->ea_data as the base for the bounds check. An "untrusted" server can use this to leak up to 8 bytes of kernel heap into the EA name comparison and influence which WSL xattr the data is interpreted as.

Affected products

• Linux Linux Kernel: from 6.6.32, before 6.6.136 (fixed in 6.6.136); from 6.9, before 6.12.83 (fixed in 6.12.83); from 6.13, before 6.18.24 (fixed in 6.18.24); from 6.19, before 6.19.14 (fixed in 6.19.14); from 7.0, before 7.0.1 (fixed in 7.0.1)

Published 2026-04-24. Last modified 2026-06-17.