Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-90066: samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.20% (FIRST EPSS).
  • Fixed version: Linux Linux 02866f063062dcc5686445c738be003de9787250, 626614df9080d7052fbe24dc90b5434717ab7a9f, 6727b7618f49401acf373fa3ec5712e2ec52e5cf; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.

Low priority for now. Upgrade to Linux Linux 02866f063062dcc5686445c738be003de9787250, 626614df9080d7052fbe24dc90b5434717ab7a9f, 6727b7618f49401acf373fa3ec5712e2ec52e5cf; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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: samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify ftrace_direct_multi_init() assigns kthread_run()'s return value to simple_tsk without an IS_ERR() check. When kthread_run() fails it returns ERR_PTR(-ENOMEM), but init still returns 0, so the module loads with simple_tsk holding an error pointer. On unload, ftrace_direct_multi_exit() then passes that ERR_PTR to kthread_stop(), leading to a null-pointer-dereference. Check the return value of kthread_run() with IS_ERR(); on failure, unregister the ftrace direct call and propagate the error code.

—No exploit Fix available
Published
Sep 17, 2026
Updated
Oct 30, 2026
EPSS
0.2% · 10th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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-2026-90066

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

    • 5.16affected
    • e1067a07cfbc5a36abad3752fafe4c79e06db1bb and later · before 02866f063062dcc5686445c738be003de9787250affected · git
    • e1067a07cfbc5a36abad3752fafe4c79e06db1bb and later · before 7a96b9f6d5ba23dbce66c8a4a242effd4c01a830affected · git
    • e1067a07cfbc5a36abad3752fafe4c79e06db1bb and later · before 98b7b2a29ae87937aa02ab9391543ef8c602cd94affected · git
    • e1067a07cfbc5a36abad3752fafe4c79e06db1bb and later · before 626614df9080d7052fbe24dc90b5434717ab7a9faffected · git
    • e1067a07cfbc5a36abad3752fafe4c79e06db1bb and later · before cf839636911d8313f3ecd098329fd0b96499e4cfaffected · git
    • e1067a07cfbc5a36abad3752fafe4c79e06db1bb and later · before 6727b7618f49401acf373fa3ec5712e2ec52e5cfaffected · git
    • before 5.16not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.157 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

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-2026-90064Sep 17, 2026 · drm/xe: Reject page faults from non-fault-mode scratch VMs
    0Monitor
  • ← EarlierCVE-2026-90065Sep 17, 2026 · net/smc: release the internal TCP sock on IPPROTO_SMC socket creation failure
    0Monitor
  • Later →CVE-2026-90067Sep 17, 2026 · libceph: validate banner payload length
    30Monitor

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 Linux02866f063062dcc5686445c738be003de9787250Vendor (CNA)
Linux Linux626614df9080d7052fbe24dc90b5434717ab7a9fVendor (CNA)
Linux Linux6727b7618f49401acf373fa3ec5712e2ec52e5cfVendor (CNA)
Linux Linux7a96b9f6d5ba23dbce66c8a4a242effd4c01a830Vendor (CNA)
Linux Linux98b7b2a29ae87937aa02ab9391543ef8c602cd94Vendor (CNA)
Linux Linuxcf839636911d8313f3ecd098329fd0b96499e4cfVendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package 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.

No nightly-computed relations.

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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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

References

Show all references (5 more)

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

All records