s390/pkey: Check length in PKEY_VERIFYPROTK ioctl (CVE-2026-64559) | HOL Guard CVE

High · CVSS 7.8CVE-2026-64559

s390/pkey: Check length in PKEY_VERIFYPROTK ioctl

Answer in brief

CVE-2026-64559 records a High severity (CVSS 7.8) vulnerability in s390/pkey: Check length in PKEY_VERIFYPROTK ioctl. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 29, 2026Updated Aug 17, 2026Source checked Sep 21, 2026First seen by HOL Aug 5, 2026Material review Aug 17, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=8fcc231ce3bea12b78bb94b280cdc03cff342435 <0a9e34ccbe772b8f321388cdbdf4f22b94e513e7 \|\| >=8fcc231ce3bea12b78bb94b280cdc03cff342435 <693bf91d4db134f9b1c2840c8e287eee3d993bac \|\| >=8fcc231ce3bea12b78bb94b280cdc03cff342435 <7e7e03848c918aa0acad5ffd75d929e3afec1554 \|\| >=8fcc231ce3bea12b78bb94b280cdc03cff342435 <b3d4ab2d7df9426f7f1d3671d7e2108f2ca6e970	0a9e34ccbe772b8f321388cdbdf4f22b94e513e7, 693bf91d4db134f9b1c2840c8e287eee3d993bac, 7e7e03848c918aa0acad5ffd75d929e3afec1554, b3d4ab2d7df9426f7f1d3671d7e2108f2ca6e970
Linux/Linuxgeneric	6.12	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 0a9e34ccbe772b8f321388cdbdf4f22b94e513e7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Check length in PKEY_VERIFYPROTK ioctl Explicitly check the buffer length request structure provided by user-space and fail, if it exceeds the buffer size.

Quoted source text, attributed separately from HOL analysis.