VulnerabilityPublished 13 Nov 2026

CVE-2026-92241: zephyrproject zephyr · Dos

Affects zephyrproject zephyrSource CVE Database V5

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Not known to be exploited · CVSS 5.7 Medium : upgrade to 4.5.0 when convenient.

Data as of 13 Nov 2026, 15:07 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

Patch: Available – fixed in 4.5.0

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

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

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

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
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: 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: None: There is no loss of confidentiality within the impacted component.
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 13 Nov 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 4.5.0.

Affected software

Product	Affected	Fixed in
zephyrprojectzephyr	Affected >=4.4.0 <4.5.0	Fixed in 4.5.0
GitHubzephyr`pkg:github/zephyr`Other threats	Affected >=4.4.0 <4.5.0	Fixed in 4.5.0

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 version 4.5.0 that changes buffer allocation to non-blocking mode (K_NO_WAIT), preventing indefinite blocking. Users should upgrade to version 4.5.0 or later to remediate this issue. No other mitigation or workaround is indicated by the vendor advisory.

Description

CVE-2026-92241 is a denial-of-service vulnerability in the Zephyr project's Bluetooth AVRCP browsing channel. It occurs due to blocking buffer allocation from a limited pool when processing large segmented L2CAP packets, causing the Bluetooth host to hang permanently. This affects Zephyr versions from 4.4.0 up to but not including 4.5.0. The issue requires a paired BR/EDR peer with the AVRCP browsing channel enabled. The flaw does not cause memory corruption or data leakage but results in a complete halt of Bluetooth host processing until reboot. A fix is available in version 4.5.0 that changes buffer allocation to non-blocking behavior, allowing recovery from resource exhaustion.

Impact

The vulnerability leads to a permanent denial-of-service condition on the Bluetooth host stack, causing all Bluetooth connections and internal processing to stop functioning until the device is rebooted. There is no impact on confidentiality or integrity, only availability is affected. The hang affects the entire Bluetooth host, not just the AVRCP component.

Summary

The vulnerability exists in the AVRCP browsing channel's L2CAP receive-buffer callback in Zephyr's Bluetooth host stack. The callback allocates buffers from a shared pool with blocking behavior (K_FOREVER). A connected browsing peer can exhaust this pool by sending large segmented SDUs without proper length bounding, causing the allocation to block indefinitely on the Bluetooth RX work queue thread. This thread is responsible for processing all Bluetooth host data and internal work items, so blocking it causes a permanent hang of the entire Bluetooth host stack. The flaw requires CONFIG_BT_CLASSIC and experimental CONFIG_BT_AVRCP_BROWSING enabled, an application registering AVRCP callbacks, and an encrypted paired BR/EDR link with the browsing channel established. The fix in Zephyr 4.5.0 changes the allocation to K_NO_WAIT, which prevents indefinite blocking and allows the application to handle resource exhaustion gracefully.

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Affected software

Description

AI analysisMachine-generated, updated 13 Nov 2026, 15:07 UTC

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