CVE-2026-43185
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
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-43185
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-43185.html
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37b
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757
Vendor advisory: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | affected | |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 6.19.6-1 |
| debian | sid | fixed | 6.19.6-1 |
| debian | trixie | affected | |
| linux-kernel | affected | 6.18.16 | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550
- https://git.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757
- https://git.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37b
- https://www.suse.com/security/cve/CVE-2026-43185.html
- https://security-tracker.debian.org/tracker/CVE-2026-43185
CWEs
CWE-674
Verify integrity in audit chain (admin only). AS-IS.