VulnerabilityPublished 14 Aug 2026Updated 4 Nov 2026

CVE-2026-12364: zephyrproject zephyr · Memory-safety

Affects zephyrproject zephyrSource CVE Database V5

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Not known to be exploited · CVSS 8.4 High : upgrade to 4.4.2 or 4.3.2 soon.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 3.1 base score

8.4High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (zephyr)	CVSS 3.1	8.4

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.4.2, 4.3.2

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Aug 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 13 Nov 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.

What to do

Upgrade zephyrproject zephyr to 4.4.2 or 4.3.2.

Affected software

Product	Affected	Fixed in
zephyrprojectzephyr	Affected >=4.4.0 <4.4.2	Fixed in 4.4.2
zephyrprojectzephyr	Affected >=2.6.0 <4.3.2	Fixed in 4.3.2
GitHubzephyr`pkg:github/zephyr`Other threats	Affected >=2.6.0 <4.3.2 >=4.4.0 <4.4.2	Fixed in 4.3.2 4.4.2

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 in Zephyr versions 4.3.2 and 4.4.2 that adds necessary validation to the syscall verifier, including bounds checks and memory read validations. Users should upgrade to these fixed versions to remediate the vulnerability. No additional mitigation is required beyond applying the official patch.

Description

CVE-2026-12364 is a memory-safety vulnerability in the Zephyr project affecting the user-space system-call verifier for z_log_msg_static_create(). The verifier failed to perform mandatory checks on user-supplied arguments, allowing unprivileged user-mode threads to pass arbitrary pointers and lengths to the kernel. This leads to kernel-mode denial of service via kernel faults and potential disclosure of arbitrary kernel memory through log messages. The vulnerability does not allow kernel memory corruption or out-of-bounds writes. Fixed in Zephyr versions 4.3.2 and 4.4.2.

Impact

An attacker with unprivileged user-mode access can cause kernel crashes (denial of service) by triggering kernel faults through invalid pointer dereferences. Additionally, if the log backend output is observable, the attacker can read and disclose arbitrary kernel memory contents via crafted log messages, breaching kernel memory confidentiality. There is no kernel memory corruption or write primitive available through this vulnerability.

Summary

The vulnerability exists in the user-space system-call verifier function z_vrfy_z_log_msg_static_create() in Zephyr's logging subsystem. It was a direct pass-through to the kernel implementation z_impl_z_log_msg_static_create() without performing required K_SYSCALL_* validation checks. Under CONFIG_USERSPACE, unprivileged user threads can invoke this syscall with attacker-controlled pointers for source, desc, package, and data. The kernel dereferences these pointers without validation, allowing reads from arbitrary kernel memory addresses. This causes kernel faults (denial of service) and may leak kernel memory content in log backend outputs, violating the user/kernel memory boundary. The fix enforces bounds checking on desc.package_len, rejects mismatched non-NULL/length parameters, and applies K_SYSCALL_MEMORY_READ() to validate memory reads, preventing out-of-bounds or kernel pointer dereferences.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2026, 11:24 UTC

Technical details

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