Linux Kernel up to 6.12.108/6.18.49/7.2.3 tracing user_events user_event_mm_dup use after free

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00+

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel up to 6.12.108/6.18.49/7.2.3. This impacts the function user_event_mm_dup of the component tracing user_events. Performing a manipulation results in use after free. This vulnerability is cataloged as CVE-2026-89750. The attack must be initiated from a local position. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. This affects the function user_event_mm_dup of the component tracing user_events. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: tracing/user_events: Clear copied tracing state before fork duplication dup_task_struct() copies user_event_mm from the parent into the child, without grabbing a reference to it. user_event_mm_dup() should replace it, but it leaves that copied pointer unmodified if user_event_mm_alloc() fails. When the child exits, user_event_mm_remove() decrements a reference the child never owned, which ultimately frees user_event_mm, while the parent still as a stale pointer to it. This creates a UAF, which KASAN reports as: BUG: KASAN: slab-use-after-free in current_user_event_mm+0x51/0x1d0 Write of size 4 at addr ffff888005010d30 by task init/44 Call Trace: <TASK> kasan_report+0xce/0x100 kasan_check_range+0x10f/0x1e0 current_user_event_mm+0x51/0x1d0 user_events_ioctl+0x82e/0x15c0 __x64_sys_ioctl+0x139/0x1c0 do_syscall_64+0xce/0x450 entry_SYSCALL_64_after_hwframe+0x77/0x7f Allocated by task 44: __kasan_kmalloc+0x8f/0xa0 __kmalloc_cache_noprof+0x180/0x3a0 user_event_mm_alloc+0x3c/0x1f0 current_user_event_mm+0x88/0x1d0 Freed by task 42: __kasan_slab_free+0x43/0x70 kfree+0x13a/0x390 process_one_work+0x696/0xf90 worker_thread+0x420/0xba0 The fix simply clears the copied pointer before any possible failure. In case of failure, the child then has nothing to free.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-89750 since 09/11/2026. The exploitability is told to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/11/2026).

Upgrading to version 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch 63b39e49a4c9d68e010e96b26fc7374f0864f2b1/25a0758cf6bdbfddac2be71124c9bd0692f4b0b1/b799f67119aff179719a0b1e12441ebbdaaf62f9/390f6bd8583d177029d9df4bea6667509e55a765 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
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: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

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: 63b39e49a4c9d68e010e96b26fc7374f0864f2b1/25a0758cf6bdbfddac2be71124c9bd0692f4b0b1/b799f67119aff179719a0b1e12441ebbdaaf62f9/390f6bd8583d177029d9df4bea6667509e55a765

Timelineinfo

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

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89750 (🔒)
GCVE (CVE): GCVE-0-2026-89750
GCVE (VulDB): GCVE-100-402609

Entryinfo

Created: 09/11/2026 22:57
Changes: 09/11/2026 22:57 (59)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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