Linux Kernel up to 7.2-rc5 ksmbd __close_file_table_ids use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.00-

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. It has been rated as very critical. The impacted element is the function __close_file_table_ids of the component ksmbd. This manipulation causes use after free. The identification of this vulnerability is CVE-2026-74522. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. It has been declared as very critical. Affected by this vulnerability is the function __close_file_table_ids of the component ksmbd. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. 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: ksmbd: fix use-after-free in __close_file_table_ids() A ksmbd_file can remain alive after logical close while another session holds a temporary reference obtained through ksmbd_lookup_fd_inode(). ksmbd_close_fd() currently marks the file closed and drops the idr-owned reference, but leaves the pointer published in the closing session's idr until the final reference is dropped. If the foreign holder performs the final ksmbd_fd_put(), __put_fd_final() supplies the foreign session's file table to __ksmbd_close_fd(). The object is then freed without being removed from its owner's idr, and the owner session later dereferences the stale pointer during file-table teardown. Remove the volatile id from the owner's idr while ksmbd_close_fd() still holds that table's lock, and clear volatile_id before dropping the idr-owned reference. A later foreign final put then only performs physical destruction and cannot remove the object from the wrong table.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-74522 since 08/15/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/15/2026).

Upgrading to version 6.6.151, 6.12.103, 6.18.44, 7.1.8 or 7.2-rc6 eliminates this vulnerability. Applying the patch 67aaec2a1fdce3e1dde46c45b5d1ef8cf22f65cd/0c3918c2cee62ec6c9de8d5c73ebfe6f833961ac/9be4a66f019ea90bd9deca70511f4f9ffebf5c6f/cffbdc86393b0235383a20c8c59bc32f16036459/e7188199eff46a636f3436356f0aae039be6dd66 is able to eliminate this problem.

Statistical analysis made it clear that VulDB provides the best quality 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: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
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: Use after free
CWE: CWE-416 / CWE-119
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 6.6.151/6.12.103/6.18.44/7.1.8/7.2-rc6
Patch: 67aaec2a1fdce3e1dde46c45b5d1ef8cf22f65cd/0c3918c2cee62ec6c9de8d5c73ebfe6f833961ac/9be4a66f019ea90bd9deca70511f4f9ffebf5c6f/cffbdc86393b0235383a20c8c59bc32f16036459/e7188199eff46a636f3436356f0aae039be6dd66

Timelineinfo

08/15/2026 Advisory disclosed
08/15/2026 +0 days CVE reserved
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74522 (🔒)
GCVE (CVE): GCVE-0-2026-74522
GCVE (VulDB): GCVE-100-390859

Entryinfo

Created: 08/15/2026 15:44
Changes: 08/15/2026 15:44 (59)
Complete: 🔍
Cache ID: 216::103

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