Linux Kernel up to 7.0.1 SMB Client cifs_mount_get_tcon privilege escalation

CVSS Meta Temp Score
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.0.1. It has been declared as problematic. This affects the function cifs_mount_get_tcon of the component SMB Client. Executing a manipulation can lead to an unknown weakness. The identification of this vulnerability is CVE-2026-31710. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 7.0.1. This vulnerability affects the function cifs_mount_get_tcon of the component SMB Client. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix dir separator in SMB1 UNIX mounts When calling cifs_mount_get_tcon() with SMB1 UNIX mounts, @cifs_sb->mnt_cifs_flags needs to be read or updated only after calling reset_cifs_unix_caps(), otherwise it might end up with missing CIFS_MOUNT_POSIXACL and CIFS_MOUNT_POSIX_PATHS bits. This fixes the wrong dir separator used in paths caused by the missing CIFS_MOUNT_POSIX_PATHS bit in cifs_sb_info::mnt_cifs_flags.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-31710 since 03/09/2026. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/30/2026).

Upgrading to version 7.0.2 or 7.1-rc1 eliminates this vulnerability. Applying the patch fbbfcf35e1ee3396631f3dc6214cb626aa9814c3/c4d3fc5844d685441befd0caaab648321013cdfd is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1346). Once again VulDB remains the best source for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure Linux
  • Red Hat OpenShift

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
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: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

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 7.0.2/7.1-rc1
Patch: fbbfcf35e1ee3396631f3dc6214cb626aa9814c3/c4d3fc5844d685441befd0caaab648321013cdfd

Timelineinfo

03/09/2026 CVE reserved
05/01/2026 +52 days Advisory disclosed
05/01/2026 +0 days VulDB entry created
06/30/2026 +60 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-31710 (🔒)
GCVE (CVE): GCVE-0-2026-31710
GCVE (VulDB): GCVE-100-360604
CERT Bund: WID-SEC-2026-1346 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 05/01/2026 16:50
Updated: 06/30/2026 21:11
Changes: 05/01/2026 16:50 (57), 05/05/2026 03:43 (7), 06/09/2026 10:22 (1), 06/30/2026 21:11 (3)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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