Linux Kernel up to 7.2.5 NFSv4 nfs4_alloc_client use after free

CVSS Meta Temp Score
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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 7.2.5. It has been declared as very critical. This affects the function nfs4_alloc_client of the component NFSv4. Executing a manipulation can lead to use after free. This vulnerability appears as CVE-2026-90151. The attack may be performed from remote. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 7.2.5 and classified as very critical. This vulnerability affects the function nfs4_alloc_client of the component NFSv4. 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. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: NFSv4: remove callback IDR entry on client allocation failure nfs4_alloc_client() allocates an NFSv4.0 callback identifier before it finishes setting up the client. If any later initialization step fails, the error path frees the nfs_client directly with nfs_free_client(). That bypasses nfs_put_client(), which is where the callback IDR entry is removed during normal teardown. A failed allocation can therefore leave cb_ident_idr pointing at a freed nfs_client. A later NFSv4.0 callback lookup by cb_ident would find the stale pointer and take a reference to it. Make the callback IDR removal helper callable by the allocation failure path, and remove the callback identifier before freeing the client. This was found by a local static-analysis checker for publish-before-free lifetime bugs and confirmed by manual inspection.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-90151 since 09/11/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/17/2026).

Upgrading to version 5.10.270, 5.15.221, 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 68c721391b761dbe38d5b0094d2bb6e8489ad92b/9bfdd0f591307b5198826a0e7a5b2f35f87acd2d/7c4812eb96bdcafb31a65b12f2aa96659429d1d4/fc95ca82d5ae598c428ab5a00ae69f8526d59371/80b1c3d5a881f7d9081aa9f46da9742878a0f893/3f2387e8bfbc4efda5d77c3a11a028d0a119c48f/5891c03e150920618db0e9c4ea2d772abacdcfd1/d05c2007b3d84ccba11dc6e9cb3202768cc72f14 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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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 5.10.270/5.15.221/6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: 68c721391b761dbe38d5b0094d2bb6e8489ad92b/9bfdd0f591307b5198826a0e7a5b2f35f87acd2d/7c4812eb96bdcafb31a65b12f2aa96659429d1d4/fc95ca82d5ae598c428ab5a00ae69f8526d59371/80b1c3d5a881f7d9081aa9f46da9742878a0f893/3f2387e8bfbc4efda5d77c3a11a028d0a119c48f/5891c03e150920618db0e9c4ea2d772abacdcfd1/d05c2007b3d84ccba11dc6e9cb3202768cc72f14

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-2026-90151 (🔒)
GCVE (CVE): GCVE-0-2026-90151
GCVE (VulDB): GCVE-100-406678

Entryinfo

Created: 09/17/2026 20:10
Changes: 09/17/2026 20:10 (59)
Complete: 🔍
Cache ID: 216::103

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