Linux Kernel up to 7.2.5 cuse cuse_exit use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.2.5. It has been classified as critical. This issue affects the function cuse_exit of the component cuse. This manipulation causes use after free. This vulnerability appears as CVE-2026-90140. The attack requires local access. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.5. It has been declared as critical. Affected by this vulnerability is the function cuse_exit of the component cuse. 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: cuse: wait for pending RCU callbacks on module exit Since commit 053fc4f755ad ("fuse: fix UAF in rcu pathwalks"), fuse_conn_put() frees the fuse_conn through call_rcu() rather than synchronously. For cuse, fc->release is cuse_fc_release(), which lives in the cuse module. If the module is removed before the RCU grace period ends, the callback jumps into freed module memory: userspace / module unload | RCU softirq ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ close(/dev/cuse) | cuse_channel_release() | fuse_dev_release() | fuse_conn_put(fch->conn) | call_rcu(delayed_release) ------+---> callback queued | rmmod cuse | cuse_exit() | cuse_channel_destroy() | ... | return | | <module text freed> | | rcu_do_batch() | delayed_release() | fc->release() | -> cuse_fc_release() | ^^^ freed text! The freed module text is unmapped by vfree(), so the jump into the stale callback triggers a page-fault Oops. If the virtual address is subsequently reused, the callback could execute unrelated code (undefined behaviour). Fix this by calling rcu_barrier() in cuse_exit() so that any pending fuse_conn release callback completes before the module is removed.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-90140 since 09/11/2026. The exploitation appears to be easy. Attacking locally is a requirement. Additional levels of successful authentication are necessary for exploitation. It demands that the victim is doing some kind of user interaction. 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).

Upgrading to version 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 7fe415e1cd8fa875be263670c0ab47109818abb6/45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e/ac5c499413385cea3e0220d6050408d50842891d/a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9/389bd349ddbcf90dbd8a4f2a4ab6e552d53df134/c40f3f24839f8404325a2099e26c2a04786ae309/4deb3edead0c0e172cc7349e8855d741d3c5e162 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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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.7
VulDB Meta Temp Score: 7.4

VulDB Base Score: 7.7
VulDB Temp Score: 7.4
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: Partially
Local: Yes
Remote: Partially

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 5.15.221/6.1.188/6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: 7fe415e1cd8fa875be263670c0ab47109818abb6/45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e/ac5c499413385cea3e0220d6050408d50842891d/a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9/389bd349ddbcf90dbd8a4f2a4ab6e552d53df134/c40f3f24839f8404325a2099e26c2a04786ae309/4deb3edead0c0e172cc7349e8855d741d3c5e162

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-2026-90140 (🔒)
GCVE (CVE): GCVE-0-2026-90140
GCVE (VulDB): GCVE-100-406663

Entryinfo

Created: 09/17/2026 20:00
Changes: 09/17/2026 20:00 (59)
Complete: 🔍
Cache ID: 216::103

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