Linux Kernel up to 6.18.41/7.1.5 fuse-uring fuse_uring_do_register connected/lock race condition

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.54+

Summaryinfo

A vulnerability labeled as problematic has been found in Linux Kernel up to 6.18.41/7.1.5. This issue affects the function fuse_uring_do_register of the component fuse-uring. Such manipulation of the argument connected/lock leads to race condition. This vulnerability is documented as CVE-2026-68095. The attack needs to be performed locally. There is not any exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.41/7.1.5 and classified as problematic. Affected by this issue is the function fuse_uring_do_register of the component fuse-uring. The manipulation of the argument connected/lock with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix race between registration and connection abortion This fixes this race: - thread a: io_uring_enter -> register sqe -> fuse_uring_create_ring_ent -> allocate ent but doesn't grab queue_ref yet - thread b: fuse_conn_destroy() -> fuse_chan_abort() -> fuse_uring_abort() is a no-op due to queue ref being 0 - thread a: grabs the queue_ref, queue_ref is now 1, rest of fuse_uring_do_register() logic executes - thread b: fuse_chan_abort() returns, fuse_chan_wait_aborted() now runs and calls "wait_event(ring->stop_waitq, atomic_read(&ring->queue_refs) == 0);" The abort/unmount thread will hang indefinitely in unkillable state as nothing will decrement queue_refs or wake stop_waitq, and the ring, queue, and ent are leaked. Fix this by checking fch->connected under fch->lock after the created ent has grabbed a ref count on the queue. This ensures that in the scenario above, it is guaranteed that we either release the queue ref and wake up stop_waitq (in case fuse_chan_wait_aborted() is already waiting) in fuse_uring_do_register() when we detect !fch->connected, or if the connection is aborted after the check, it is guaranteed that the async teardown worker will be running in the background cleaning up ents and decrementing the ent's ref on the queue, which will unblock the eventual queue and ring teardown.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-68095 since 07/30/2026. The exploitation is known to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit.

Upgrading to version 6.18.42, 7.1.6 or 7.2-rc1 eliminates this vulnerability. Applying the patch 3bca70235a706de76fe9a81defd37d987062c686/2cd945492bc5b472e814272e88b731bb9bb17629/952b5d36f6a298f57c52a59e72076c69386a8aaf is able to eliminate this problem.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
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: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

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 6.18.42/7.1.6/7.2-rc1
Patch: 3bca70235a706de76fe9a81defd37d987062c686/2cd945492bc5b472e814272e88b731bb9bb17629/952b5d36f6a298f57c52a59e72076c69386a8aaf

Timelineinfo

07/30/2026 CVE reserved
08/10/2026 +11 days Advisory disclosed
08/10/2026 +0 days VulDB entry created
08/10/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-68095 (🔒)
GCVE (CVE): GCVE-0-2026-68095
GCVE (VulDB): GCVE-100-387446

Entryinfo

Created: 08/10/2026 14:42
Changes: 08/10/2026 14:42 (60)
Complete: 🔍
Cache ID: 216::103

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