VulnerabilityPublished 21 Sep 2026Updated 4 Nov 2026

CVE-2026-17050: zephyrproject zephyr · Use After Free

Affects zephyrproject zephyrSource CVE Database V5

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Not known to be exploited · CVSS 5.7 Medium : upgrade to 4.4.2 or 4.3.2 when convenient.

Data as of 5 Nov 2026, 11:40 UTC

CVSS 3.1 base score

5.7Medium

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	5.7

EPSS: 0.2% chance of exploitation in 30 days – higher than 14% 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:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Attack Vector: Physical
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: High

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

Attack Vector: Physical: The attack requires the attacker to physically touch or manipulate the vulnerable component. Physical interaction may be brief or persistent.
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 21 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 5 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 >=4.1.0 <4.3.2	Fixed in 4.3.2
GitHubzephyr`pkg:github/zephyr`Other threats	Affected >=4.1.0 <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 addresses the double free by nullifying the pointer after freeing the buffer. Users should upgrade to these fixed versions to remediate the vulnerability. No additional mitigation is required if running these patched versions.

Description

CVE-2026-17050 is a use-after-free vulnerability in the experimental USB host stack of Zephyr OS. It occurs when a per-device configuration-descriptor buffer is freed multiple times due to improper pointer handling after certain USB descriptor read failures. This can lead to a double free on a dedicated heap, causing either a deterministic denial of service via kernel panic or heap corruption that may allow memory corruption. The vulnerability affects Zephyr versions 4.1.0 through before 4.3.2 and 4.4.0 through before 4.4.2. A fix is available in versions 4.3.2 and 4.4.2, which nullifies the pointer after freeing to prevent double free.

Impact

The vulnerability allows a malicious USB device to cause a deterministic denial of service on the USB host by triggering a kernel panic through a double free detection mechanism in heap hardening builds. On builds without heap hardening, it can corrupt the heap's free list, potentially leading to memory corruption. However, exploitation beyond denial of service is limited due to the small size of the dedicated heap and the experimental, disabled-by-default status of the USB host stack.

Summary

The vulnerability arises in Zephyr's experimental USB host stack where the per-device configuration-descriptor buffer (udev->cfg_desc) is allocated from a dedicated usb_device_heap. On three failure paths during configuration descriptor reads, the buffer is freed but the pointer is left dangling. Subsequent cleanup attempts check only if the pointer is non-null and free the buffer again, causing a double free. This double free triggers either a kernel panic on builds with heap hardening enabled or heap corruption on builds without it. The attack is driven by a malicious or malformed USB device that can cause descriptor read failures during enumeration. The vulnerability is fixed by setting the pointer to NULL after freeing, preventing double free on cleanup. The affected versions are >=4.1.0 <4.3.2 and >=4.4.0 <4.4.2, with fixes in 4.3.2 and 4.4.2.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2026, 11:27 UTC

Technical details

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