CVE Intelligence
Unknown

CVE-2026-99039 — memstick: core: wait for request completion before freeing card

In the Linux kernel, the following vulnerability has been resolved: memstick: core: wait for request completion before freeing card In memstick_alloc_card() and memstick_set_rw_addr(), wait_for_completion_timeout() is used to wait for device identification and address configuration requests to complete. The memstick subsystem does not provide an abort or cancellation callback in struct memstick_host for in-flight requests. If wait_for_completion_timeout() expires (for instance, when a USB transfer or command retry is delayed), memstick_alloc_card() returns an error and frees the memstick_dev structure via kfree(card). However, the host controller driver (such as rtsx_usb_ms) is still running the request asynchronously in worker context. When the transfer eventually finishes, the driver writes into host->req->data, which points to memory inside the already freed card structure. This leads to a KASAN slab-use-after-free write: BUG: KASAN: slab-use-after-free in ms_read_bytes+0x8fe/0x990 Write of size 1 at addr ffff88813c188079 by task kworker/1:5/5239 Workqueue: events rtsx_usb_ms_handle_req Call Trace: ms_read_bytes+0x8fe/0x990 drivers/memstick/host/rtsx_usb_ms.c:450 rtsx_usb_ms_issue_cmd drivers/memstick/host/rtsx_usb_ms.c:477 [inline] rtsx_usb_ms_handle_req+0x557/0x1a00 drivers/memstick/host/rtsx_usb_ms.c:531 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 Allocated by task 1662: memstick_alloc_card drivers/memstick/core/memstick.c:383 [inline] memstick_check+0x2c1/0x10d0 drivers/memstick/core/memstick.c:452 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 Freed by task 1662: kfree+0x20c/0x650 mm/slub.c:6792 memstick_alloc_card drivers/memstick/core/memstick.c:420 [inline] memstick_check+0x72b/0x10d0 drivers/memstick/core/memstick.c:452 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 Host controller drivers (rtsx_usb_ms, jmb38x_ms, tifm_ms, r592) already implement their own hardware and bus timeouts, and callers in mspro_block and ms_block already rely on wait_for_completion() unconditionally. Replace wait_for_completion_timeout() with wait_for_completion() in memstick_set_rw_addr() and memstick_alloc_card() so that the card structure is never freed while an asynchronous request is in flight.

Published Oct 23, 2026 · Updated Oct 30, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.17%
ahead of 6% of scored CVEs · Oct 30, 2026
Affects
Linux
Linux
CVSS base
—
Score not published yet.

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < c3ab92542475d59ae685cbb294e70ca4d0ba38e9≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < 810580cf60edc75c9891c2de3225e4cda78e4d9f≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < f2795c50144d528dabc2cf2fd53c0f0c63a823a1≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < 3af81770e2011c6ac7bb597a4af2e4f3591f928c≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < aa0a37b5024d921e96ac4f8f487c8bfbf1f1a582version 2.6.25≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < b90f33ad9179c69658342323382bfed158f88cb9≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < 1c23da6f148089d59b3d3e9b2e7f1eefa927cab9
and 1 more ≥ baf8532a147d5b76681ce040e2c8f25a3f0e718d and < a2f1aa3341f185ca52103dc4908647570b208855
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.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 30, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 23, 2026
  • Affected products added · linux/linux
    Oct 23, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Received
    Oct 23, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 23, 2026 · Alertas do Telegram
  • CVE published
    Oct 23, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 23, 2026 – Oct 30, 2026
  • 1× Official description updated · Oct 23, 2026 – Oct 23, 2026

References

8 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
  • CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
  • CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
  • CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
  • CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
  • 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-2026-99039 is "memstick: core: wait for request completion before freeing card", 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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