Linux Kernel up to 6.12.108/6.18.49/7.2.3 Serial UART imx_uart_probe imx_uart_ports use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.8$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 vulnerability affects the function imx_uart_probe of the component Serial UART. The manipulation of the argument imx_uart_ports leads to use after free. This vulnerability is documented as CVE-2026-89740. The attack needs to be performed locally. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. This issue affects the function imx_uart_probe of the component Serial UART. The manipulation of the argument imx_uart_ports with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: serial: imx: serialize imx_uart_ports[] lifetime imx_uart_probe() publishes its devm-allocated port in imx_uart_ports[] before uart_add_one_port() because console setup uses the table. The entry is not cleared when adding the port fails or after removal, leaving a dangling pointer. A sibling probe can register the shared console through that stale entry. This was reproduced under KASAN on QEMU mcimx6ul-evk by unbinding a sibling UART, unbinding the console UART and rebinding the sibling. Keep the entry valid through uart_remove_one_port(), then clear it. Protect port addition and removal together with their table updates so sibling operations cannot interleave. Reject an occupied slot rather than clobbering an active port during a duplicate-line probe.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-89740 since 09/11/2026. The exploitation is known to be easy. An attack has to be approached locally. The exploitation needs additional levels of successful authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD 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 681696ae9e4a28bdf54893c807dfe4a6c08e30a5/28b932202fcdbeb2ef58d89ce4363f480433c234/7429dce56a73bc080a8c072edb167106f73a08ae/8b0b29fdcb47907ae0296b8fe829e918e05e300f 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: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
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: 681696ae9e4a28bdf54893c807dfe4a6c08e30a5/28b932202fcdbeb2ef58d89ce4363f480433c234/7429dce56a73bc080a8c072edb167106f73a08ae/8b0b29fdcb47907ae0296b8fe829e918e05e300f

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-2026-89740 (🔒)
GCVE (CVE): GCVE-0-2026-89740
GCVE (VulDB): GCVE-100-402581

Entryinfo

Created: 09/11/2026 22:37
Changes: 09/11/2026 22:37 (60)
Complete: 🔍
Cache ID: 216::103

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