VulnerabilityPublished 23 Oct 2026

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

Source GCVE Database

Authoritative record:CVE-2026-99024· High

Not known to be exploited · fixed in c108feca0a096f8db25d1b69130035025e9e936d : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in c108feca0a096f8db25d1b69130035025e9e936d, 262062c01f5a817104c88bf6eacb7c6ffdc7018d, 681adbc9c7a820279582a295e183fa6a1d1b4ec4 +2

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.

ghsa-qp8f-jjvm-547w

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2, < c108feca0a096f8db25d1b69130035025e9e936d	Fixed in c108feca0a096f8db25d1b69130035025e9e936d
LinuxLinux	Affected ≥ 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2, < 262062c01f5a817104c88bf6eacb7c6ffdc7018d	Fixed in 262062c01f5a817104c88bf6eacb7c6ffdc7018d
LinuxLinux	Affected ≥ 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2, < 681adbc9c7a820279582a295e183fa6a1d1b4ec4	Fixed in 681adbc9c7a820279582a295e183fa6a1d1b4ec4
LinuxLinux	Affected ≥ 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2, < 8cae1605be8a047ae3a62df07b9474d61462c4f6	Fixed in 8cae1605be8a047ae3a62df07b9474d61462c4f6
LinuxLinux	Affected ≥ 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2, < 2f7240f0a6fd83df274fc0a2abf0609b4e6bd388	Fixed in 2f7240f0a6fd83df274fc0a2abf0609b4e6bd388
LinuxLinux	Affected =4.12	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: optee: register TEE devices only once fully initialized optee_probe() called tee_device_register() on both the client and the supplicant device before the rest of struct optee had been initialized. tee_device_register() calls cdev_device_add(), which does two things at once: it creates /dev/tee0 and /dev/teepriv0, and it links the device into the tee class so that class_find_device() can find it. From that moment on the device is reachable both from user space via tee_open() and from kernel space via tee_client_open_context(). The only gate in teedev_open() is tee_device_get(), which merely checks that teedev->desc is non-NULL, which was already set by tee_device_alloc(). Therefore, there is effectively no gate at all. A context opened in that window can run against a struct optee where - optee->call_queue.mutex is not initialized by optee_cq_init() - optee->supp mutex and completions is not initialized by optee_supp_init() - optee->rpmb_dev_mutex is not initialized yet, - the message argument cache is not initialized by optee_shm_arg_cache_init() - optee->ctx is still NULL Any open session or invoke during this window takes uninitialized mutexes and dereferences a NULL pointer. Fix it by moving both tee_device_register() calls down to the point where all of struct optee is set up. [JW: adding fixes and cc]

References

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