Linux Kernel up to 7.3-rc3 cifs cifs_chan_skip_or_disable use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.00

Summaryinfo

A vulnerability categorized as very critical has been discovered in Linux Kernel up to 6.6.157/6.12.111/6.18.53/7.2.7/7.3-rc3. Affected is the function cifs_chan_skip_or_disable of the component cifs. Executing a manipulation can lead to use after free. This vulnerability is handled as CVE-2026-98261. The attack can be executed remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.6.157/6.12.111/6.18.53/7.2.7/7.3-rc3. This vulnerability affects the function cifs_chan_skip_or_disable of the component cifs. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server use-after-free in cifs_chan_skip_or_disable() When a secondary channel is no longer supported by the server, cifs_chan_skip_or_disable() drops the channel reference with cifs_put_tcp_session() and then continues to use the server pointer by calling cifs_signal_cifsd_for_reconnect() on it and reading its primary_server pointer. cifs_put_tcp_session() can drop the last reference of the channel and tear it down, so both the channel and the primary server (whose reference is also dropped by cifs_put_tcp_session()) can be freed before they are signaled for reconnect. Signal the channel and the primary server and capture the primary server pointer before dropping the channel reference with cifs_put_tcp_session().

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-98261 since 09/25/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 10/06/2026).

Upgrading to version 6.6.158, 6.12.112, 6.18.54, 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch 0338489960ddad6368bce55e8adbc176c523093d/edd52eae5fcfb8433b6bb0e7cd98db438fe01227/fcc0a935bb6e37ecbf7e4335061309f896f35780/7a1b27780b113583a94256d58dabfe7c0d9286e7/717e0a25036b6c92cecace30913b2d874a4c22b8 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: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
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: Use after free
CWE: CWE-416 / CWE-119
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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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.158/6.12.112/6.18.54/7.2.8/7.3-rc4
Patch: 0338489960ddad6368bce55e8adbc176c523093d/edd52eae5fcfb8433b6bb0e7cd98db438fe01227/fcc0a935bb6e37ecbf7e4335061309f896f35780/7a1b27780b113583a94256d58dabfe7c0d9286e7/717e0a25036b6c92cecace30913b2d874a4c22b8

Timelineinfo

09/25/2026 CVE reserved
10/06/2026 +11 days Advisory disclosed
10/06/2026 +0 days VulDB entry created
10/06/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98261 (🔒)
GCVE (CVE): GCVE-0-2026-98261
GCVE (VulDB): GCVE-100-414226

Entryinfo

Created: 10/06/2026 13:50
Changes: 10/06/2026 13:50 (59)
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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