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HIGH

CVE-2026-80921

CVSS v3

8.8

HIGH

EPSS Score

0.2 %

exploit probability, as of 2026-09-28

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Description

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.

Technical details

Published
2026-09-09
Last Modified
2026-09-10

Frequently asked questions

What is CVE-2026-80921?

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.

Is CVE-2026-80921 actively exploited?

Active exploitation of CVE-2026-80921 has not been confirmed. Its EPSS score was 0.2% on 2026-09-28, the estimated probability of exploitation in the next 30 days.

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

CVE-2026-80921 has a CVSS v3 base score of 8.8 (HIGH severity).

Is CVE-2026-80921 affecting your environment?

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