VulnerabilityPublished 17 Sep 2026Updated 30 Oct 2026

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

Source GCVE Database

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Authoritative record:CVE-2026-90066· Medium

Not known to be exploited · fixed in cf839636911d8313f3ecd098329fd0b96499e4cf : update Linux kernel when convenient.

Data as of 30 Oct 2026, 19:18 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in cf839636911d8313f3ecd098329fd0b96499e4cf, 626614df9080d7052fbe24dc90b5434717ab7a9f, 6727b7618f49401acf373fa3ec5712e2ec52e5cf +3

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-h42m-cfhq-9g8c

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ e1067a07cfbc5a36abad3752fafe4c79e06db1bb, < cf839636911d8313f3ecd098329fd0b96499e4cf	Fixed in cf839636911d8313f3ecd098329fd0b96499e4cf
LinuxLinux	Affected ≥ e1067a07cfbc5a36abad3752fafe4c79e06db1bb, < 626614df9080d7052fbe24dc90b5434717ab7a9f	Fixed in 626614df9080d7052fbe24dc90b5434717ab7a9f
LinuxLinux	Affected ≥ e1067a07cfbc5a36abad3752fafe4c79e06db1bb, < 6727b7618f49401acf373fa3ec5712e2ec52e5cf	Fixed in 6727b7618f49401acf373fa3ec5712e2ec52e5cf
LinuxLinux	Affected ≥ e1067a07cfbc5a36abad3752fafe4c79e06db1bb, < 02866f063062dcc5686445c738be003de9787250	Fixed in 02866f063062dcc5686445c738be003de9787250
LinuxLinux	Affected ≥ e1067a07cfbc5a36abad3752fafe4c79e06db1bb, < 98b7b2a29ae87937aa02ab9391543ef8c602cd94	Fixed in 98b7b2a29ae87937aa02ab9391543ef8c602cd94
LinuxLinux	Affected ≥ e1067a07cfbc5a36abad3752fafe4c79e06db1bb, < 7a96b9f6d5ba23dbce66c8a4a242effd4c01a830	Fixed in 7a96b9f6d5ba23dbce66c8a4a242effd4c01a830

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available as the vulnerability has been resolved by adding proper error checking of kthread_run() return values. Users should apply the official patch or update to a kernel version that includes this fix. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's ftrace direct multi-modify module occurs due to missing error checking after kthread_run() invocation. If kthread_run() fails and returns an error pointer, the module incorrectly proceeds as if successful, leading to a null-pointer dereference when unloading the module.

References

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