# CVE-2026-64558: CVE-2026-64558

Status: published. Published: 2026-07-29. Updated: 2026-11-03.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

Not reported in collected sources.

## Severity and prioritization

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H; source: NVD: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact total; source NVD SSVC: 134c704f-9b21-4f2e-91b3-4a467353bcc0

- Weaknesses: CWE-122

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/02028a24e26d85262ab9c8fc4344e1f3503007fc (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/1ac287e2af9a9112fe271427ef45eceb26bce8b4 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/433e5e70cdc1edf382d28d08a885b22e2b98b7da (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/614aa0491c7a190556c2345dddee0b6f5ed90989 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

## Provenance

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64558; retrieved 2026-11-03; source updated 2026-11-03

Revision: 4d2ee13858fbae25b453d0b0f427bb2d6cdafcf464450a609b9bc2c5d51fdd5f

Canonical: https://y2.dev/cve/CVE-2026-64558

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