CVE-2026-43185

critical

Description

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)

References

https://git.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37b

https://git.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757

https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550

Details

Source: Mitre, NVD

Published: 2026-05-06

Updated: 2026-05-11

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00017