Linux Kernel up to 6.18.38/7.1.3 fuse-uring fuse_uring_commit data authenticity

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.18.38/7.1.3. Affected by this vulnerability is the function fuse_uring_commit of the component fuse-uring. Such manipulation leads to data authenticity. This vulnerability is uniquely identified as CVE-2026-64264. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.18.38/7.1.3. Affected by this issue is the function fuse_uring_commit of the component fuse-uring. The manipulation with an unknown input leads to a data authenticity vulnerability. Using CWE to declare the problem leads to CWE-345. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix EFAULT clobber in fuse_uring_commit copy_from_user() returns the number of bytes not copied as an unsigned residual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit stores that residual in ssize_t err, sets req->out.h.error to -EFAULT, then jumps to out: with err still holding the positive residual. err = copy_from_user(&req->out.h, &ent->headers->in_out, sizeof(req->out.h)); if (err) { req->out.h.error = -EFAULT; goto out; /* err is the positive residual */ } ... out: fuse_uring_req_end(ent, req, err); fuse_uring_req_end() then runs if (error) req->out.h.error = error; which overwrites the just-assigned -EFAULT with the positive residual. FUSE callers such as fuse_simple_request() test err < 0 to detect failure, so the positive value is interpreted as success and the caller proceeds with an uninitialised or partial req->out.args. Fix by assigning err = -EFAULT in the failure branch before jumping to out, so fuse_uring_req_end() receives a negative errno and sets req->out.h.error to -EFAULT.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-64264 since 07/19/2026. The exploitation is known to be easy. The attack may be launched remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/26/2026).

The vulnerability scanner Nessus provides a plugin with the ID 329933 (Linux Distros Unpatched Vulnerability : CVE-2026-64264), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch 0483fffdeeb363f320e6bf5fc0f0306007507306/fe604c08d874648a69187f6380e5c7858627dc04/3a0a8bc51a13951c5141262bf770eeea3e0b6228 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at Tenable (329933). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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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
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Data authenticity
CWE: CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 329933
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-64264

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.39/7.1.4/7.2-rc1
Patch: 0483fffdeeb363f320e6bf5fc0f0306007507306/fe604c08d874648a69187f6380e5c7858627dc04/3a0a8bc51a13951c5141262bf770eeea3e0b6228

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/26/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64264 (🔒)
GCVE (CVE): GCVE-0-2026-64264
GCVE (VulDB): GCVE-100-383042

Entryinfo

Created: 07/25/2026 11:50
Updated: 07/26/2026 21:57
Changes: 07/25/2026 11:50 (59), 07/26/2026 21:57 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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