What is CVE-2026-31539?

CVE-2026-31539 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-2026-31539 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-31539?

CVE-2026-31539 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-2026-31539?

Yes, CVE-2026-31539 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-2026-31539 actively exploited?

CVE-2026-31539 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-31539

High

In the Linux kernel, the following vulnerability has been resolved: smb: smbdirect: introduce 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.

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-2026-31539 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/6e3c5052f9686192e178806e017b7377155f4bab
Patch
Kernel patch commit
https://git.kernel.org/stable/c/e811e60e1cc79923c4388146eb1fa26a7482731e
Patch
Kernel patch commit
https://git.kernel.org/stable/c/f99996870222b598914a1f49d7375dc23752c237
Patch

Details

CVE ID CVE-2026-31539

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-2026-31539?

CVE-2026-31539 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-2026-31539 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-31539?

CVE-2026-31539 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-2026-31539?

Yes — CVE-2026-31539 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-2026-31539 actively exploited?

No — CVE-2026-31539 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.