What is CVE-2026-43185?

CVE-2026-43185 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, classified as a Uncontrolled Recursion flaw (CWE-674), affecting Linux kernel versions from 5.15 onward and patched in 6.18.16, 6.19.6 and 7.0. CVE-2026-43185 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43185?

CVE-2026-43185 has a CVSS score of 9.8 out of 10, rated Critical severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-43185?

Yes, CVE-2026-43185 has been patched. Fixed versions include 6.18.16, 6.19.6 and 7.0. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43185 actively exploited?

CVE-2026-43185 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Uncontrolled Recursion (CWE-674)?

The product does not properly control the amount of recursion which triggers resource consumption. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/674.html

CVE-2026-43185

Critical

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)

Package Linux Kernel

Published 2026-05-06

Last modified 2026-05-11

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.8

out of 10

Critical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-674

CVE-2026-43185 is a Uncontrolled Recursion vulnerability

What is Uncontrolled Recursion?

The product does not properly control the amount of recursion which triggers resource consumption. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.15 and later are affected. Fixed in 6.18.16, 6.19.6, 7.0 and their respective stable series.

Affected from

≥ 5.15

Fixed in

✓ 6.18.16 6.18.x ✓ 6.19.6 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-43185 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550
Patch
Kernel patch commit
https://git.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757
Patch
Kernel patch commit
https://git.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37b
Patch

Details

CVE ID CVE-2026-43185

Severity Critical

CVSS score 9.8 / 10

CVSS version 3.1

Published 2026-05-06

Modified 2026-05-11

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43185?

CVE-2026-43185 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 , classified as an Uncontrolled Recursion flaw (CWE-674) . It affects Linux kernel versions from 5.15 onward and has been patched in 6.18.16, 6.19.6 and 7.0. CVE-2026-43185 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43185?

CVE-2026-43185 has a CVSS score of 9.8 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-43185?

Yes — CVE-2026-43185 has been patched. Fixed versions include 6.18.16, 6.19.6 and 7.0. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43185 actively exploited?

No — CVE-2026-43185 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Uncontrolled Recursion (CWE-674)?

The product does not properly control the amount of recursion which triggers resource consumption. View CWE-674 on MITRE CWE →