Linux Kernel up to 6.12.108/6.18.49/7.2.3 jbd2 journal_shrink_one_cp_list nr_to_scan privileges management

CVSS Meta Temp Score
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CTI Interest Score
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7.2$0-$5k0.00+

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. It has been rated as critical. The impacted element is the function journal_shrink_one_cp_list of the component jbd2. This manipulation of the argument nr_to_scan causes privileges management. This vulnerability is handled as CVE-2026-89567. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.12.108/6.18.49/7.2.3 and classified as critical. Affected by this vulnerability is the function journal_shrink_one_cp_list of the component jbd2. The manipulation of the argument nr_to_scan with an unknown input leads to a privileges management vulnerability. The CWE definition for the vulnerability is CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: jbd2: bound shrinker scans by examined checkpoint buffers The jbd2 shrinker currently accounts only checkpoint buffers that it successfully releases against nr_to_scan. Busy buffers therefore do not consume the scan budget. If a checkpoint transaction contains mostly busy buffers, the shrinker can scan its entire checkpoint list while holding journal->j_list_lock. Large checkpoint lists can result in excessive lock hold times and leave other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls. Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for every buffer examined, including busy buffers. Pass NULL from checkpoint cleanup paths so their existing full-list behavior is preserved. This restores the scan-budget semantics that existed before journal_shrink_one_cp_list() was changed to always scan a complete checkpoint list.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-89567 since 09/11/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/12/2026). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

Upgrading to version 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch edf5fcd0469b7467bd5b37a79502c8d9c3257dbb/71c6b872c746465fa4b5def239cb296173ca8216/c2c0fb364685b8996c357d3b050394959b29d6e0/15cb16496446b94e67f7abcb049b8e2c75cd3d02 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
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: Privileges management
CWE: CWE-269 / CWE-266
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 6.12.109/6.18.50/7.2.4/7.3-rc1
Patch: edf5fcd0469b7467bd5b37a79502c8d9c3257dbb/71c6b872c746465fa4b5def239cb296173ca8216/c2c0fb364685b8996c357d3b050394959b29d6e0/15cb16496446b94e67f7abcb049b8e2c75cd3d02

Timelineinfo

09/11/2026 CVE reserved
09/11/2026 +0 days VulDB entry created
09/12/2026 +0 days Advisory disclosed
09/12/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89567 (🔒)
GCVE (CVE): GCVE-0-2026-89567
GCVE (VulDB): GCVE-100-402871

Entryinfo

Created: 09/12/2026 01:20
Changes: 09/12/2026 01:20 (60)
Complete: 🔍
Cache ID: 216::103

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