What is CVE-2026-90191?

CVE-2026-90191 is a High severity Linux kernel vulnerability with a CVSS score of 8.4 out of 10, affecting Linux kernel versions from 6.18 onward and patched in 6.18.52, 7.2.6 and 7.3-rc1. CVE-2026-90191 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-90191?

CVE-2026-90191 has a CVSS score of 8.4 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-90191?

Yes, CVE-2026-90191 has been patched. Fixed versions include 6.18.52, 7.2.6 and 7.3-rc1. 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-2026-90191 actively exploited?

CVE-2026-90191 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-90191

High

In the Linux kernel, the following vulnerability has been resolved: mailbox: riscv-sbi-mpxy: validate RPMI notification lengths The SBI return value controls how many bytes are copied from shared memory into the RPMI notification buffer. It is not validated against the negotiated shared-memory size before that copy. The event walker also uses a reversed loop condition and can inspect a short event record. Validate the complete notification length before copying it, iterate only while a full event header remains, and stop when a declared event payload extends beyond the copied notification data.

Package Linux Kernel

Published 2026-09-17

Last modified 2026-09-18

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

8.4

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.18 and later are affected. Fixed in 6.18.52, 7.2.6, 7.3-rc1 and their respective stable series.

Affected from

≥ 6.18

Fixed in

✓ 6.18.52 6.18.x ✓ 7.2.6 7.2.x ✓ 7.3-rc1

References

3 total

Details

CVE ID CVE-2026-90191

Severity High

CVSS score 8.4 / 10

CVSS version 3.1

Published 2026-09-17

Modified 2026-09-18

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-90191?

CVE-2026-90191 is a High severity Linux kernel vulnerability with a CVSS score of 8.4 out of 10 . It affects Linux kernel versions from 6.18 onward and has been patched in 6.18.52, 7.2.6 and 7.3-rc1. CVE-2026-90191 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-90191?

CVE-2026-90191 has a CVSS score of 8.4 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-90191?

Yes. CVE-2026-90191 has been patched. Fixed versions include 6.18.52, 7.2.6 and 7.3-rc1. 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-2026-90191 actively exploited?

No. CVE-2026-90191 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.