What is CVE-2026-80921?

CVE-2026-80921 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10, affecting Linux kernel versions from 4.20 onward and patched in 5.10.269, 5.15.220, 6.1.187 and others. CVE-2026-80921 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-80921?

CVE-2026-80921 has a CVSS score of 8.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Is there a patch available for CVE-2026-80921?

Yes, CVE-2026-80921 has been patched. Fixed versions include 5.10.269, 5.15.220, 6.1.187 and others. If you are running Linux kernel 4.20 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-80921 actively exploited?

CVE-2026-80921 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-80921

High

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: vsie: zero stale crypto bits When shadowing crypto access bits from a format0 apcb (crycb 0 or 1), the bits 64..255 are unchanged from whatever is in the vsie page in the crycb and thus in the apcb. This gives a nested guest potential access to a device no longer available. Zero out the remaining bits.

Package Linux Kernel

Published 2026-09-09

Last modified 2026-09-10

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

8.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 4.20 and later are affected. Fixed in 5.10.269, 5.15.220, 6.1.187, 6.6.156, 6.12.108, 6.18.49, 7.1.13, 7.2.3, 7.3-rc1 and their respective stable series.

Affected from

≥ 4.20

Fixed in

✓ 5.10.269 5.10.x ✓ 5.15.220 5.15.x ✓ 6.1.187 6.1.x ✓ 6.6.156 6.6.x ✓ 6.12.108 6.12.x ✓ 6.18.49 6.18.x ✓ 7.1.13 7.1.x ✓ 7.2.3 7.2.x ✓ 7.3-rc1

References

9 total

Showing 5 of 9 references View all on NVD

Details

CVE ID CVE-2026-80921

Severity High

CVSS score 8.8 / 10

CVSS version 3.1

Published 2026-09-09

Modified 2026-09-10

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-80921?

CVE-2026-80921 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 . It affects Linux kernel versions from 4.20 onward and has been patched in 5.10.269, 5.15.220, 6.1.187 and others. CVE-2026-80921 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-80921?

CVE-2026-80921 has a CVSS score of 8.8 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:C/C:H/I:H/A:H.
Is there a patch available for CVE-2026-80921?

Yes. CVE-2026-80921 has been patched. Fixed versions include 5.10.269, 5.15.220, 6.1.187 and others. If you are running Linux kernel 4.20 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-80921 actively exploited?

No. CVE-2026-80921 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.