Linux Kernel up to 6.12.110/6.18.52 virtio-fs virtio_fs_setup_vqs double free

CVSS Meta Temp Score
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CTI Interest Score
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8.6$5k-$25k0.22+

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.12.110/6.18.52 and classified as very critical. Affected is the function virtio_fs_setup_vqs of the component virtio-fs. This manipulation causes double free. This vulnerability appears as CVE-2026-93827. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.12.110/6.18.52. Affected by this vulnerability is the function virtio_fs_setup_vqs of the component virtio-fs. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. 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: virtio-fs: avoid double-free on failed queue setup virtio_fs_setup_vqs() allocates fs->vqs and fs->mq_map before calling virtio_find_vqs(). If virtio_find_vqs() fails, the error path frees both pointers and returns an error to virtio_fs_probe(). virtio_fs_probe() then drops the last kobject reference, and virtio_fs_ktype_release() frees fs->vqs and fs->mq_map again. This leaves dangling pointers in struct virtio_fs and can trigger a double-free during probe failure cleanup. Set fs->vqs and fs->mq_map to NULL immediately after kfree() in the virtio_fs_setup_vqs() error path so that the later kobject release sees an uninitialized state and kfree(NULL) becomes harmless. This can be reproduced when a broken virtio-fs device advertises more request queues than the transport actually provides. In that case virtio_find_vqs() fails while setting up the extra queue, and the probe path reaches the double-free cleanup sequence.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-93827 since 09/18/2026. The exploitation appears to be easy. The attack can be launched remotely. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/24/2026).

Upgrading to version 6.12.111 or 6.18.53 eliminates this vulnerability. Applying the patch 3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad/20ef4739b329bb09cff11dd2458795a50674658e/6af3330ec5d5fb8c06c04eb520a71cf73ea5a765 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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: 9.0
VulDB Meta Temp Score: 8.6

VulDB Base Score: 9.0
VulDB Temp Score: 8.6
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: Double free
CWE: CWE-415 / 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 6.12.111/6.18.53
Patch: 3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad/20ef4739b329bb09cff11dd2458795a50674658e/6af3330ec5d5fb8c06c04eb520a71cf73ea5a765

Timelineinfo

09/18/2026 CVE reserved
09/24/2026 +6 days Advisory disclosed
09/24/2026 +0 days VulDB entry created
09/24/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-93827 (🔒)
GCVE (CVE): GCVE-0-2026-93827
GCVE (VulDB): GCVE-100-409573

Entryinfo

Created: 09/24/2026 19:22
Changes: 09/24/2026 19:22 (59)
Complete: 🔍
Cache ID: 216::103

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