What is CVE-2026-89571?

CVE-2026-89571 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10, affecting Linux kernel versions from 6.15 onward and patched in 6.18.50, 7.2.4 and 7.3-rc1. CVE-2026-89571 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89571?

CVE-2026-89571 has a CVSS score of 7.1 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Is there a patch available for CVE-2026-89571?

Yes, CVE-2026-89571 has been patched. Fixed versions include 6.18.50, 7.2.4 and 7.3-rc1. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89571 actively exploited?

CVE-2026-89571 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89571

High

In the Linux kernel, the following vulnerability has been resolved: cxl/features: bound fwctl command payload to the input buffer fwctl_cmd_rpc() copies cmd->in_len bytes into inbuf = kvzalloc(cmd->in_len) and passes inbuf and in_len to ->fw_rpc(). The CXL callback cxlctl_fw_rpc() ignores in_len and never checks the user-controlled op_size against it. cxlctl_set_feature() bounds op_size only from below (op_size <= sizeof(feat_in->hdr)) and then reads op_size - sizeof(hdr) bytes from feat_in->feat_data via cxl_set_feature(). With a small in_len and a large op_size the first memcpy() already reads past the kvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox payload and sent to the device, and a large enough op_size can walk into unmapped memory and oops the kernel. The Get paths pin op_size to a fixed size but likewise read the input struct without checking in_len. Reject, at the single dispatch point, any request whose fixed header plus op_size does not fit in the copied-in buffer. The lower-bound test guards the subtraction and ensures op_size was copied in before it is read.

Package Linux Kernel

Published 2026-09-11

Last modified 2026-09-13

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.1

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.15 and later are affected. Fixed in 6.18.50, 7.2.4, 7.3-rc1 and their respective stable series.

Affected from

≥ 6.15

Fixed in

✓ 6.18.50 6.18.x ✓ 7.2.4 7.2.x ✓ 7.3-rc1

References

3 total

Details

CVE ID CVE-2026-89571

Severity High

CVSS score 7.1 / 10

CVSS version 3.1

Published 2026-09-11

Modified 2026-09-13

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-89571?

CVE-2026-89571 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 . It affects Linux kernel versions from 6.15 onward and has been patched in 6.18.50, 7.2.4 and 7.3-rc1. CVE-2026-89571 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89571?

CVE-2026-89571 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.
Is there a patch available for CVE-2026-89571?

Yes. CVE-2026-89571 has been patched. Fixed versions include 6.18.50, 7.2.4 and 7.3-rc1. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89571 actively exploited?

No. CVE-2026-89571 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.