Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 smb-client smb3_zero_range allocation of resources

CVSS Meta Temp Score
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CTI Interest Score
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4.4$0-$5k0.00+

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1. It has been declared as problematic. The affected element is the function smb3_zero_range of the component smb-client. Executing a manipulation can lead to allocation of resources. The identification of this vulnerability is CVE-2026-98126. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 and classified as problematic. This vulnerability affects the function smb3_zero_range of the component smb-client. The manipulation with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. As an impact it is known to affect integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: smb/client: validate new EOF for zero range When FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE, smb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing the file to grow beyond the caller's file-size limit. Fix this by calling inode_newsize_ok() before sending the zero-range request when the operation would extend EOF. Reproducer, using a file on a CIFS mount: bash -c ' FILE=/mnt/cifs/repro trap "" SIGXFSZ ulimit -f 3072 truncate -s 2M "$FILE" fallocate --zero-range -o 0 -l 4M "$FILE" echo "fallocate rc=$?" stat -c "file size=%s" "$FILE" ' Before this change, the operation succeeds despite the 3 MiB limit: fallocate rc=0 file size=4194304 After this change, fallocate fails and leaves the file at 2 MiB.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-98126 since 09/25/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc2 eliminates this vulnerability. Applying the patch 3673f057b64abfa957e8ae84448db69369a5091a/06a4f9049cb6dc319bceec2dc813ba89add8b828/f320ca20c273a26cd779bdb2b2e4b076a95c76f6/88972e35750792e717af287dc71f42a03b5cbce4 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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: 4.6
VulDB Meta Temp Score: 4.4

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
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: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
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 6.12.111/6.18.53/7.2.7/7.3-rc2
Patch: 3673f057b64abfa957e8ae84448db69369a5091a/06a4f9049cb6dc319bceec2dc813ba89add8b828/f320ca20c273a26cd779bdb2b2e4b076a95c76f6/88972e35750792e717af287dc71f42a03b5cbce4

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98126 (🔒)
GCVE (CVE): GCVE-0-2026-98126
GCVE (VulDB): GCVE-100-409954

Entryinfo

Created: 09/25/2026 13:14
Changes: 09/25/2026 13:14 (59)
Complete: 🔍
Cache ID: 216::103

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