CVE-2026-43185: Linux Kernel

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in smb_direct_prepare_negotiation() smb_direct_prepare_negotiation() casts an unsigned __u32 value from sp->max_recv_size and req->preferred_send_size to a signed int before computing min_t(int, ...). A maliciously provided preferred_send_size of 0x80000000 will return as smaller than max_recv_size, and then be used to set the maximum allowed alowed receive size for the next message. By sending a second message with a large value (>1420 bytes) the attacker can then achieve a heap buffer overflow. This fix replaces min_t(int, ...) with min_t(u32)

Affected products

• Linux Linux Kernel: from 5.15, before 6.18.16 (fixed in 6.18.16); from 6.19, before 6.19.6 (fixed in 6.19.6); version 7.0 only

Published 2026-05-06. Last modified 2026-06-17.