# CVE-2026-99035: mmc: mtk-sd: Cancel request timeout work on remove

CVE-2026-99035 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-99035, released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-99035
- Priority: Routine
- CVSS: 4.7 (Moderate)
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 23, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-99035

## Description

In the Linux kernel, the following vulnerability has been resolved:  mmc: mtk-sd: Cancel request timeout work on remove  The driver queues req_timeout while a request is active. msdc_request_done() uses cancel_delayed_work(), which does not wait for a timeout callback that has already started.  The timeout callback calls mmc_request_done(), which wakes the request waiter, and then continues to use host->dev_comp and check the SDIO IRQ. During unbind, msdc_drv_remove() can return and the managed mmc_host can be freed before the callback finishes.  KASAN reported use-after-free accesses in msdc_request_done() and msdc_recheck_sdio_irq() in each of three unbind tests.  The same tests completed without a kernel diagnostic after this change.  Call cancel_delayed_work_sync() after mmc_remove_host() has stopped new requests and before the driver releases the host resources.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.113-1 | [DEBIAN-CVE-2026-99035](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99035.md) | Oct 24, 2026 |
| Linux | linux Debian 14 | 7.2.11-1 | [DEBIAN-CVE-2026-99035](https://patchblox.com/security/data/fix/linux/debian-cve-2026-99035.md) | Oct 24, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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