Linux Kernel up to 7.2.5 hci_sync adv_timeout_expire memory leak

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.00-

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel up to 6.1.187/6.6.156/6.12.109/6.18.51/7.2.5. This issue affects the function adv_timeout_expire of the component hci_sync. This manipulation causes memory leak. This vulnerability is registered as CVE-2026-90254. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.1.187/6.6.156/6.12.109/6.18.51/7.2.5 and classified as very critical. Affected by this vulnerability is the function adv_timeout_expire of the component hci_sync. The manipulation with an unknown input leads to a memory leak vulnerability. The CWE definition for the vulnerability is CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: free the advertising instance on the failure and cancel paths adv_timeout_expire() hands a kmalloc()ed instance byte to hci_cmd_sync_queue() with a NULL destroy callback, and only adv_timeout_expire_sync() frees it. That leaks on two paths: - the return value is not checked, and hci_cmd_sync_queue() does not take ownership when it fails (-ENETDOWN, -ENODEV, -ENOMEM); - a cancelled entry is not released, as _hci_cmd_sync_cancel_entry() does not free entry->data when there is no destroy callback. hci_cmd_sync_clear() cancels every pending entry when the controller is unregistered. Free the buffer from a destroy callback, and in the caller when the entry could not be queued at all.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-90254 since 09/11/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/17/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch c2019224a766245b7db39d87fdfe84c3fdc879d9/193182c6467f508a8a61d5db506d796ffed6eee6/2e3d827cd56865c14f6ca118bbccd7801091fb21/9c3b6c1413bd0b4993642d987616331f84d9b7f5/bb5ca1cc7744c41c59002bd6523714a685ae6595/120d8dc042e3d45073bb6e50ee7b058a0b182627 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory leak
CWE: CWE-401 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: c2019224a766245b7db39d87fdfe84c3fdc879d9/193182c6467f508a8a61d5db506d796ffed6eee6/2e3d827cd56865c14f6ca118bbccd7801091fb21/9c3b6c1413bd0b4993642d987616331f84d9b7f5/bb5ca1cc7744c41c59002bd6523714a685ae6595/120d8dc042e3d45073bb6e50ee7b058a0b182627

Timelineinfo

09/11/2026 CVE reserved
09/17/2026 +6 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90254 (🔒)
GCVE (CVE): GCVE-0-2026-90254
GCVE (VulDB): GCVE-100-406795

Entryinfo

Created: 09/17/2026 21:13
Changes: 09/17/2026 21:13 (59)
Complete: 🔍
Cache ID: 216::103

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