What is CVE-2026-89751?

CVE-2026-89751 is a unscored severity Linux kernel vulnerability, affecting Linux kernel versions from 5.19 onward and patched in 6.1.188, 6.6.157, 6.12.109 and others. CVE-2026-89751 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89751?

CVE-2026-89751 has a CVSS score of pending NVD analysis out of 10, rated awaiting scoring severity.

Is there a patch available for CVE-2026-89751?

Yes, CVE-2026-89751 has been patched. Fixed versions include 6.1.188, 6.6.157, 6.12.109 and others. If you are running Linux kernel 5.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89751 actively exploited?

CVE-2026-89751 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89751

In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix off-by-one in port I/O handling handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use: u64 mask = GENMASK(BITS_PER_BYTE * size, 0); GENMASK(h, l) includes bit h. For size=1 (INB), this produces GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8 bits). The mask is one bit too wide for all I/O sizes. Fix the mask calculation.

Package Linux Kernel

Published 2026-09-11

Last modified 2026-09-14

Patch available

Yes

Affected versions

Linux kernel versions 5.19 and later are affected. Fixed in 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4, 7.3-rc1 and their respective stable series.

Affected from

≥ 5.19

Fixed in

✓ 6.1.188 6.1.x ✓ 6.6.157 6.6.x ✓ 6.12.109 6.12.x ✓ 6.18.50 6.18.x ✓ 7.2.4 7.2.x ✓ 7.3-rc1

References

6 total

Showing 5 of 6 references View all on NVD

Frequently asked questions

What is CVE-2026-89751?

CVE-2026-89751 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.19 onward and has been patched in 6.1.188, 6.6.157, 6.12.109 and others. CVE-2026-89751 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
Is there a patch available for CVE-2026-89751?

Yes. CVE-2026-89751 has been patched. Fixed versions include 6.1.188, 6.6.157, 6.12.109 and others. If you are running Linux kernel 5.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89751 actively exploited?

No. CVE-2026-89751 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.