Review reviewHigh

CVE-2026-64558

Linux

In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Check length in pkey_pckmo handler implementation Explicitly check the length of the target buffer in the pkey_pckmo implementation of the key_to_protkey() handler function. The handler function fails, if the generated output data exceeds the length of the provided target buffer.

CVSS: 7.8
EPSS: -
CISA KEV: Not listed
Published: 2026.07.30

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 7.8

Vulnerability overview

Affected product and versions

Product: Linux
Affected versions: >= 8fcc231ce3bea12b78bb94b280cdc03cff342435 < 02028a24e26d85262ab9c8fc4344e1f3503007fc, >= 8fcc231ce3bea12b78bb94b280cdc03cff342435 < 433e5e70cdc1edf382d28d08a885b22e2b98b7da, >= 8fcc231ce3bea12b78bb94b280cdc03cff342435 < 614aa0491c7a190556c2345dddee0b6f5ed90989, >= 8fcc231ce3bea12b78bb94b280cdc03cff342435 < 1ac287e2af9a9112fe271427ef45eceb26bce8b4, >= 6.12
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Linux and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE: Not available