Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-64558: s390/pkey: Check length in pkey_pckmo handler implementation

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 02028a24e26d85262ab9c8fc4344e1f3503007fc, 1ac287e2af9a9112fe271427ef45eceb26bce8b4, 433e5e70cdc1edf382d28d08a885b22e2b98b7da.

Low priority for now. Upgrade to Linux Linux 02028a24e26d85262ab9c8fc4344e1f3503007fc, 1ac287e2af9a9112fe271427ef45eceb26bce8b4, 433e5e70cdc1edf382d28d08a885b22e2b98b7da or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jul 29, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 1th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-64558

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.12affected
    • 8fcc231ce3bea12b78bb94b280cdc03cff342435 and later · before 02028a24e26d85262ab9c8fc4344e1f3503007fcaffected · git
    • 8fcc231ce3bea12b78bb94b280cdc03cff342435 and later · before 433e5e70cdc1edf382d28d08a885b22e2b98b7daaffected · git
    • 8fcc231ce3bea12b78bb94b280cdc03cff342435 and later · before 614aa0491c7a190556c2345dddee0b6f5ed90989affected · git
    • 8fcc231ce3bea12b78bb94b280cdc03cff342435 and later · before 1ac287e2af9a9112fe271427ef45eceb26bce8b4affected · git
    • before 6.12not affected · semver
    • 6.12.97 and later · up to and including 6.12.*not affected · semver
    • 6.18.40 and later · up to and including 6.18.*not affected · semver
    • 7.1.5 and later · up to and including 7.1.*not affected · semver
    • 7.2 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-develbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debug-devel-matchedbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-develbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-64k-devel-matchedbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debug-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debug-develbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debug-devel-matchedbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-aarch64before 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-ppc64lebefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-s390xbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-debuginfo-common-x86_64before 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-develbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-devel-matchedbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-docbefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-64k-debug-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-64k-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-debug-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6
Red Hat:rhel_eus:9.6::appstreamkernel-rt-debuginfobefore 0:5.14.0-570.146.1.el9_60:5.14.0-570.146.1.el9_6

+70

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-64556Jul 29, 2026 · perf/core: Detach event groups during remove_on_exec
    31Monitor
  • ← EarlierCVE-2026-64557Jul 29, 2026 · Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()
    35Monitor
  • Later →CVE-2026-64559Jul 29, 2026 · s390/pkey: Check length in PKEY_VERIFYPROTK ioctl
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux02028a24e26d85262ab9c8fc4344e1f3503007fcVendor (CNA)
Linux Linux1ac287e2af9a9112fe271427ef45eceb26bce8b4Vendor (CNA)
Linux Linux433e5e70cdc1edf382d28d08a885b22e2b98b7daVendor (CNA)
Linux Linux614aa0491c7a190556c2345dddee0b6f5ed90989Vendor (CNA)
debian:linux6.12.100-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:5.14.0-570.146.1.el9_6 · Red Hat:rhel_eus:9.6::appstreamPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-6393910 days apartKVM: SEV: Compute the correct max length of the in-GHCB scratch area
    37Monitor
  • CVE-2026-23178165 days apartHID: i2c-hid: fix potential buffer overflow in i2c_hid_get_report()
    31Monitor
  • CVE-2025-68795197 days apartethtool: Avoid overflowing userspace buffer on stats query
    31Monitor
  • CVE-2026-645244 days apartdrm/hyperv: validate resolution_count and fix WIN8 fallback
    30Monitor
  • CVE-2026-6829312 days apartnet/mlx5: Fix MCIA register buffer overflow on 32 dword reads
    28Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-122 · Heap-based Buffer Overflow

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records