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NVD / CVE Program· CNA Linux

CVE-2025-40223: most: usb: Fix use-after-free in hdm_disconnect

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
  • Fixed version: Linux Linux 33daf469f5294b9d07c4fc98216cace9f4f34cc6, 3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6, 4b1270902609ef0d935ed2faa2ea6d122bd148f5; azl3 kernel 6.6.112.1-2 on Azure Linux 3.0 6.6.117.1-1.

Low priority for now. Upgrade to Linux Linux 33daf469f5294b9d07c4fc98216cace9f4f34cc6, 3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6, 4b1270902609ef0d935ed2faa2ea6d122bd148f5; azl3 kernel 6.6.112.1-2 on Azure Linux 3.0 6.6.117.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: most: usb: Fix use-after-free in hdm_disconnect hdm_disconnect() calls most_deregister_interface(), which eventually unregisters the MOST interface device with device_unregister(iface->dev). If that drops the last reference, the device core may call release_mdev() immediately while hdm_disconnect() is still executing. The old code also freed several mdev-owned allocations in hdm_disconnect() and then performed additional put_device() calls. Depending on refcount order, this could lead to use-after-free or double-free when release_mdev() ran (or when unregister paths also performed puts). Fix by moving the frees of mdev-owned allocations into release_mdev(), so they happen exactly once when the device is truly released, and by dropping the extra put_device() calls in hdm_disconnect() that are redundant after device_unregister() and most_deregister_interface(). This addresses the KASAN slab-use-after-free reported by syzbot in hdm_disconnect(). See report and stack traces in the bug link below.

—No exploit Fix available
Published
Dec 4, 2025
Updated
Oct 19, 2026
EPSS
0.2% · 10th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.9affected
    • 97a6f772f36b7f52bcfa56a581bbd2470cffe23d and later · before 5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831affected · git
    • 97a6f772f36b7f52bcfa56a581bbd2470cffe23d and later · before 578eb18cd111addec94c43f61cd4b4429e454809affected · git
    • 97a6f772f36b7f52bcfa56a581bbd2470cffe23d and later · before 33daf469f5294b9d07c4fc98216cace9f4f34cc6affected · git
    • 97a6f772f36b7f52bcfa56a581bbd2470cffe23d and later · before 72427dc6f87523995f4e6ae35a948bb2992cabceaffected · git
    • 97a6f772f36b7f52bcfa56a581bbd2470cffe23d and later · before f93a84ffb884d761a9d4e869ba29c238711e81f1affected · git
    • 97a6f772f36b7f52bcfa56a581bbd2470cffe23d and later · before 3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6affected · git
    • 97a6f772f36b7f52bcfa56a581bbd2470cffe23d and later · before 4b1270902609ef0d935ed2faa2ea6d122bd148f5affected · git
    • before 5.9not affected · semver
    • 5.10.246 and later · up to and including 5.10.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.158-16.1.158-1
Debian:13linuxbefore 6.12.57-16.12.57-1
Debian:14linuxbefore 6.17.6-16.17.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2025-40221Dec 4, 2025 · media: pci: mg4b: fix uninitialized iio scan data
    0Monitor
  • ← EarlierCVE-2025-40222Dec 4, 2025 · tty: serial: sh-sci: fix RSCI FIFO overrun handling
    0Monitor
  • Later →CVE-2025-40224Dec 4, 2025 · hwmon: (cgbc-hwmon) Add missing NULL check after devm_kzalloc()
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux33daf469f5294b9d07c4fc98216cace9f4f34cc6Vendor (CNA)
Linux Linux3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6Vendor (CNA)
Linux Linux4b1270902609ef0d935ed2faa2ea6d122bd148f5Vendor (CNA)
Linux Linux578eb18cd111addec94c43f61cd4b4429e454809Vendor (CNA)
Linux Linux5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831Vendor (CNA)
Linux Linux72427dc6f87523995f4e6ae35a948bb2992cabceVendor (CNA)
Linux Linuxf93a84ffb884d761a9d4e869ba29c238711e81f1Vendor (CNA)
azl3 kernel 6.6.112.1-2 on Azure Linux 3.06.6.117.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.158-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records