CVE-2026-89440 (CVSS 7.8)

Description

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.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0016

Probability of exploitation

0.06%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/088eaa92fcebaa6b957ccf9635afdf39643a577d https://git.kernel.org/stable/c/2550f89589caad7402d618d7dffc038582c94b6b https://git.kernel.org/stable/c/5bb5327b92aae17e91c7228953c350a6ee3c94e8 https://git.kernel.org/stable/c/806409f12fdb14c9e4c56a64494c9b75f356cd49 https://git.kernel.org/stable/c/c2b8a624911999399cc14822fec3e35032b3cee4 https://git.kernel.org/stable/c/d045596706d1b25d38af4a79980b017639fea9d1 https://git.kernel.org/stable/c/dde5b9c91e9fc64e54a2f186d3ae95868b4dbb02 https://git.kernel.org/stable/c/efe7f25dd27e35063477b4b0e7eed3675669fd99

Frequently Asked Questions

What is CVE-2026-89440? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-89440? +

CVE-2026-89440 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0016, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-89440? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-89440