Linux Kernel up to 6.12.112/6.18.54/7.2.8/7.3-rc4 xfs xlog_recover_iunlink_bucket 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-$25k1.82-

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.112/6.18.54/7.2.8/7.3-rc4. It has been classified as very critical. Affected is the function xlog_recover_iunlink_bucket of the component xfs. This manipulation causes use after free. This vulnerability appears as CVE-2026-98443. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.112/6.18.54/7.2.8/7.3-rc4. It has been declared as very critical. Affected by this vulnerability is the function xlog_recover_iunlink_bucket of the component xfs. 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. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: xfs: fix cursor and pointer handling when recovering iunlink buckets LOLLM pointed out a bug in xlog_recover_iunlink_bucket: 1. We don't null out prev_ip after releasing it, which can lead to UAF problems if the inodegc flush call in the loop fails. at which point I noticed even more bugs: 2. If the inodegc flush inside the loop fails, we also leak @ip. 3. We set prev_agino to agino having already advanced agino, which results in inodes with i_prev_unlinked set to itself. 4. If we exit the bottom of the loop with prev_ip set, then prev_ip aliases ip and we also set its i_prev_unlinked to itself. Bugs 3 and 4 introduce loops into the unlinked list, though these loops don't surface because we immediately flush each unlinked inode after loading it. Fix all of these issues.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-98443 since 09/25/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/18/2026).

Upgrading to version 6.12.113, 6.18.55, 7.2.9 or 7.3-rc5 eliminates this vulnerability. Applying the patch 8c9d5b8a96d6b93eb24e07b4163c89341ba29bd1/66a2179d02668f8df44b1a249899006f3ba38ea0/961c717e6bf0e53c2c2b1fe4aef1add9390fedab/65f39d09d73718611cee40399179323b5d4ead00 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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Version

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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: Use after free
CWE: CWE-416 / CWE-119
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 6.12.113/6.18.55/7.2.9/7.3-rc5
Patch: 8c9d5b8a96d6b93eb24e07b4163c89341ba29bd1/66a2179d02668f8df44b1a249899006f3ba38ea0/961c717e6bf0e53c2c2b1fe4aef1add9390fedab/65f39d09d73718611cee40399179323b5d4ead00

Timelineinfo

09/25/2026 CVE reserved
10/18/2026 +23 days Advisory disclosed
10/18/2026 +0 days VulDB entry created
10/18/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98443 (🔒)
GCVE (CVE): GCVE-0-2026-98443
GCVE (VulDB): GCVE-100-421783

Entryinfo

Created: 10/18/2026 17:40
Changes: 10/18/2026 17:40 (59)
Complete: 🔍
Cache ID: 216::103

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