Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5 ksmbd memory leak

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5. It has been rated as critical. This impacts an unknown function of the component ksmbd. The manipulation leads to memory leak. This vulnerability is traded as CVE-2026-90169. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5 and classified as critical. This issue affects an unknown function of the component ksmbd. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ksmbd: free preauth sessions on connection teardown SMB3.1.1 multichannel binding preserves the preauthentication hash in a preauth_session between the NTLM negotiate and authenticate requests. The binding NTLM negotiate allocates this object and returns STATUS_MORE_PROCESSING_REQUIRED. If the client disconnects before it sends the authenticate request, neither the authenticate nor error cleanup paths free the object. Release any remaining preauthentication sessions when tearing down the connection. Initialize the list when allocating the connection so that this cleanup is safe regardless of the negotiated dialect.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-90169 since 09/11/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. 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 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch effcf48d79d8aa53113d8289e140746f25ceb62c/b62b1ebb25f0a19067ed5b1a86036b2dc98be44f/a41a98ee16ae038751b6639decadaa3ce15ca18a/8e2ebc77678832e981adc008d25cd8f67d08ebc4/06c7b1d731bc105a8644f1b70165ba8b9416cbab is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
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 6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: effcf48d79d8aa53113d8289e140746f25ceb62c/b62b1ebb25f0a19067ed5b1a86036b2dc98be44f/a41a98ee16ae038751b6639decadaa3ce15ca18a/8e2ebc77678832e981adc008d25cd8f67d08ebc4/06c7b1d731bc105a8644f1b70165ba8b9416cbab

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-2026-90169 (🔒)
GCVE (CVE): GCVE-0-2026-90169
GCVE (VulDB): GCVE-100-406679

Entryinfo

Created: 09/17/2026 20:13
Changes: 09/17/2026 20:13 (58)
Complete: 🔍
Cache ID: 216::103

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