CVE-2026-43185
CRITICALksmbd: fix signededness bug in smb_direct_prepare_negotiation()
Title source: cnaDescription
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)
Scores
CVSS v3
9.8
EPSS
0.0005
EPSS Percentile
16.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-674
Status
published
Products (10)
Linux/Linux
< 5.15
Linux/Linux
0626e6641f6b467447c81dd7678a69c66f7746cf - 55abc475d096da4a5356b6efb0cfdc6156bc1550
Linux/Linux
0626e6641f6b467447c81dd7678a69c66f7746cf - 6b4f875aac344cdd52a1f34cc70ed2f874a65757
Linux/Linux
0626e6641f6b467447c81dd7678a69c66f7746cf - ceae058eb707ddd0d68f0872f9d9f23b7c30c37b
Linux/Linux
5.15
Linux/Linux
6.18.16 - 6.18.*
Linux/Linux
6.19.6 - 6.19.*
Linux/Linux
7.0
linux/linux_kernel
7.0 rc1
linux/linux_kernel
5.15 - 6.18.16
Published
May 06, 2026
Tracked Since
May 06, 2026