VulnerabilityPublished 26 Oct 2026Updated 27 Oct 2026

CVE-2026-99024: Linux kernel · optee: register TEE devices only once fully initialized

Affects Linux kernelSource GCVE Database

Authoritative record:CVE-2026-99024· High

Not known to be exploited.

Data as of 28 Oct 2026, 01:57 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.10linux`pkg:deb/ubuntu/linux?arch=source&distro=stonking`Other threats	Affected 7.0.0-14.14 – 7.3.0-9.9 6 affected builds	Fixed in–
Ubuntu 26.10linux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=stonking`Other threats	Affected 7.0.0-1004.4 – 7.3.0-1003.3 5 affected builds	Fixed in–
Ubuntu 26.10linux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=stonking`Other threats	Affected 7.0.0-1004.4 – 7.3.0-1003.3 5 affected builds	Fixed in–
Ubuntu 26.10linux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonking`Other threats	Affected =7.0.0-1004.4 =7.3.0-1002.3 =7.3.0-1003.4	Fixed in–
Ubuntu 26.10linux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=stonking`Other threats	Affected 7.0.0-1003.3 – 7.3.0-1003.3 5 affected builds	Fixed in–
Ubuntu 26.10linux-oracle`pkg:deb/ubuntu/linux-oracle?arch=source&distro=stonking`Other threats	Affected 7.0.0-1003.3 – 7.3.0-1003.3 5 affected builds	Fixed in–

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 that moves the tee_device_register() calls until after the full initialization of the optee structure. Users should apply the updated Linux kernel versions that include this fix. No additional mitigation steps are indicated.

Description

CVE-2026-99024 is a vulnerability in the Linux kernel's optee driver where TEE devices were registered before full initialization, allowing access to uninitialized structures. This could lead to dereferencing NULL pointers and using uninitialized mutexes during a race window. The issue is fixed by delaying device registration until full initialization of the optee structure is complete.

Impact

During the window between device registration and full initialization, user or kernel space could open a context and invoke operations on an incompletely initialized optee structure. This could result in dereferencing NULL pointers and using uninitialized mutexes, potentially causing kernel crashes or undefined behavior. There is no indication of remote code execution or privilege escalation from the provided data.

Summary

In the Linux kernel optee driver, tee_device_register() was called prematurely on both client and supplicant devices before the optee structure was fully initialized. This premature registration made the devices accessible from user and kernel space while critical mutexes and pointers were uninitialized, potentially causing dereferences of NULL pointers and use of uninitialized mutexes. The fix involves moving the tee_device_register() calls to after the entire optee structure is properly set up.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-99024
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:26.10, Ubuntu:26.04:LTS

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Oct 2026, 01:57 UTC

Technical details

References

Community reviews

Related threats