CVE-2026-43185

EUVD-2026-27748
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)
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.8 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 40%
Affected Products (NVD)
VendorProductVersion
linuxlinux_kernel
5.15 ≤
𝑥
< 6.18.16
linuxlinux_kernel
6.19 ≤
𝑥
< 6.19.6
linuxlinux_kernel
7.0:rc1
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
linux
bookworm
vulnerable
bookworm (security)
vulnerable
bullseye
5.10.223-1
fixed
bullseye (security)
5.10.257-1
fixed
forky
7.0.12-2
fixed
sid
7.0.13-1
fixed
trixie
vulnerable
trixie (security)
vulnerable