CVE-2026-43185

critical
Published 2026-05-06 · Modified 2026-05-11
CVSS v3
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2
VIR risk
9.8

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)

Predictions

Exploit likelihood
97%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-43185

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-43185.html

vendor Authored 2026-05-27

Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37b

vendor Authored 2026-05-27

Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757

vendor Authored 2026-05-27

Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550

OS impact

OSVersionStatusFixed in
suse slesaffected
debian debianbookwormaffected
debian debianbullseyefixed0
debian debianforkyfixed6.19.6-1
debian debiansidfixed6.19.6-1
debian debiantrixieaffected
linux linux-kernelaffected6.18.16
linux linux-kernel7.0affected

References

CWEs

CWE-674

Verify integrity in audit chain (admin only). AS-IS.