CVE-2026-99038 — memstick: rtsx_usb_ms: complete requests after eject instead of dropping them
In the Linux kernel, the following vulnerability has been resolved: memstick: rtsx_usb_ms: complete requests after eject instead of dropping them memstick_check() can pass its host->removing check just before rtsx_usb_ms_drv_remove() sets eject/removing. Its next request is then silently dropped: rtsx_usb_ms_request() skips schedule_work() once eject is set, and drv_remove's cancel_work_sync() can also cancel a queued handle_req before it picks the request up. Nobody completes card->mrq_complete. Once memstick core waits for requests without a timeout ("memstick: core: wait for request completion before freeing card"), this hangs removal: memstick_check() never returns and memstick_remove_host() blocks in flush_workqueue(): INFO: task kworker/u10:3:65 blocked for more than 20 seconds. Workqueue: kmemstick memstick_check __wait_for_common memstick_check INFO: task kworker/1:1:33 blocked for more than 20 seconds. Workqueue: usb_hub_wq hub_event __flush_workqueue memstick_remove_host rtsx_usb_ms_drv_remove Never drop a request. rtsx_usb_ms_request() always schedules handle_req, and handle_req fails requests with -ENOMEDIUM once eject is set, without touching the device. drv_remove flushes handle_req instead of cancelling it, and cancels it only after memstick_remove_host(), when no new request can arrive, so it cannot run on a freed host. The host_mutex drain in drv_remove is removed: handle_req always leaves host->req NULL when it finishes, so the drain never had anything to do, and it would now race with handle_req.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < f2c181e1d58e911804e14543b2f1cc6b23a0d4d6≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < 5b599e28aeb3684772aef64f46cc6f25f4c67128≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < d7e811c3a49cd5cff529c157df886719e09370ec≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < 5616da0f92339328fa1472876df51555e15ad340≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < c96ca94425b076dc398d929366e378d1e22ec794version 3.16≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < c48245ef696e590e92cbfb622625642bec8dbbad≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < 602a00d75d2ab079c9ab7c0d7b56ae436e604148 and 1 more≥ 99451dceeb5fdd789f0a2eeb3ee029e80d2ccc40 and < 8e4eda6e1b00624820fea1d35508d7422330ee25 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 24, 2026 → Oct 30, 2026 · 7 reading(s) · max 0.21%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 3× References added · Oct 23, 2026 – Oct 30, 2026
- 1× Official description updated · Oct 23, 2026 – Oct 23, 2026
References
10 on the record
- git.kernel.org/stable/c/f2c181e1d58e911804e14543b2f1cc6b23a0d4d6
- git.kernel.org/stable/c/c48245ef696e590e92cbfb622625642bec8dbbad
- git.kernel.org/stable/c/5b599e28aeb3684772aef64f46cc6f25f4c67128
- nvd.nist.gov/vuln/detail/CVE-2026-99038
- git.kernel.org/stable/c/602a00d75d2ab079c9ab7c0d7b56ae436e604148
- git.kernel.org/stable/c/c96ca94425b076dc398d929366e378d1e22ec794
- github.com/advisories/GHSA-95v5-2rxr-2qx7
- git.kernel.org/stable/c/5616da0f92339328fa1472876df51555e15ad340
- git.kernel.org/stable/c/8e4eda6e1b00624820fea1d35508d7422330ee25
- git.kernel.org/stable/c/d7e811c3a49cd5cff529c157df886719e09370ec
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-99038 is "memstick: rtsx_usb_ms: complete requests after eject instead of dropping them", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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