What is CVE-2026-31538?

CVE-2026-31538 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10, affecting Linux kernel versions from 6.18 onward and patched in 6.18.11, 6.19.1 and 7.0. CVE-2026-31538 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-31538?

CVE-2026-31538 has a CVSS score of 7.5 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-31538?

Yes, CVE-2026-31538 has been patched. Fixed versions include 6.18.11, 6.19.1 and 7.0. If you are running Linux kernel 6.18 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-31538 actively exploited?

CVE-2026-31538 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-31538

High

In the Linux kernel, the following vulnerability has been resolved: smb: server: make use of smbdirect_socket.recv_io.credits.available The logic off managing recv credits by counting posted recv_io and granted credits is racy. That's because the peer might already consumed a credit, but between receiving the incoming recv at the hardware and processing the completion in the 'recv_done' functions we likely have a window where we grant credits, which don't really exist. So we better have a decicated counter for the available credits, which will be incremented when we posted new recv buffers and drained when we grant the credits to the peer. This fixes regression Namjae reported with the 6.18 release.

Package Linux Kernel

Published 2026-04-24

Last modified 2026-04-28

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.5

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.18 and later are affected. Fixed in 6.18.11, 6.19.1, 7.0 and their respective stable series.

Affected from

≥ 6.18

Fixed in

✓ 6.18.11 6.18.x ✓ 6.19.1 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-31538 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/26ad87a2cfb8c1384620d1693a166ed87303046e
Patch
Kernel patch commit
https://git.kernel.org/stable/c/66c082e3d4651e8629a393a9e182b01eb50fb0a3
Patch
Kernel patch commit
https://git.kernel.org/stable/c/809cbd31aa4f87a1b889532244c9cf30eb022385
Patch

Details

CVE ID CVE-2026-31538

Severity High

CVSS score 7.5 / 10

CVSS version 3.1

Published 2026-04-24

Modified 2026-04-28

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-31538?

CVE-2026-31538 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 6.18 onward and has been patched in 6.18.11, 6.19.1 and 7.0. CVE-2026-31538 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-31538?

CVE-2026-31538 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-31538?

Yes — CVE-2026-31538 has been patched. Fixed versions include 6.18.11, 6.19.1 and 7.0. If you are running Linux kernel 6.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-31538 actively exploited?

No — CVE-2026-31538 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.