Linux Kernel up to 6.12.108/6.18.49/7.2.3 via-sdmmc via_sdc_isr null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k0.00+

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 6.12.108/6.18.49/7.2.3. This affects the function via_sdc_isr of the component via-sdmmc. This manipulation causes null pointer dereference. This vulnerability is tracked as CVE-2026-89440. The attack is restricted to local execution. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.12.108/6.18.49/7.2.3 and classified as very critical. Affected by this vulnerability is the function via_sdc_isr of the component via-sdmmc. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. 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: mmc: via-sdmmc: stop card-detect handling on probe failure request_irq() registers the SD card-detect interrupt and the probe enables it before mmc_add_host() runs. If mmc_add_host() fails, the error path only unmaps the registers and returns: the interrupt stays registered, so the handler keeps running against the host once it is freed. via_sdc_isr() dereferences sdhost and its MMIO base and schedules carddet_work, which via_sdc_card_detect() also runs against freed memory through its container_of() dereference. Add a probe-error path that disables and frees the interrupt and cancels carddet_work before unmapping. carddet_work can re-enable the device interrupt via via_reset_pcictrl(), which restores PCIINTCTRL, so mask it again after cancelling the work. This issue was found by an in-house static analysis tool and confirmed by manual code review.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-89440 since 09/11/2026. The exploitation appears to be easy. An attack has to be approached locally. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. The price for an exploit might be around USD at the moment (estimation calculated on 09/12/2026).

Upgrading to version 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch efe7f25dd27e35063477b4b0e7eed3675669fd99/2550f89589caad7402d618d7dffc038582c94b6b/c2b8a624911999399cc14822fec3e35032b3cee4/088eaa92fcebaa6b957ccf9635afdf39643a577d 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: 8.2
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: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

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: efe7f25dd27e35063477b4b0e7eed3675669fd99/2550f89589caad7402d618d7dffc038582c94b6b/c2b8a624911999399cc14822fec3e35032b3cee4/088eaa92fcebaa6b957ccf9635afdf39643a577d

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-2026-89440 (🔒)
GCVE (CVE): GCVE-0-2026-89440
GCVE (VulDB): GCVE-100-402817

Entryinfo

Created: 09/12/2026 00:51
Changes: 09/12/2026 00:51 (22), 09/12/2026 00:52 (37)
Complete: 🔍
Cache ID: 216::103

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

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