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NVD / CVE Program· CNA Linux

CVE-2026-31726: usb: gadget: uvc: fix NULL pointer dereference during unbind race

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.11% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 0587de744615628c38e33ddc1601160a5ea8c50a, 0c00ec409d7b2bce3fcac73188b79a141db7cfda, 1aa9356881ee4ed414bf72d0c56d915492cb5345.

Low priority for now. Upgrade to Linux Linux 0587de744615628c38e33ddc1601160a5ea8c50a, 0c00ec409d7b2bce3fcac73188b79a141db7cfda, 1aa9356881ee4ed414bf72d0c56d915492cb5345 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: usb: gadget: uvc: fix NULL pointer dereference during unbind race Commit b81ac4395bbe ("usb: gadget: uvc: allow for application to cleanly shutdown") introduced two stages of synchronization waits totaling 1500ms in uvc_function_unbind() to prevent several types of kernel panics. However, this timing-based approach is insufficient during power management (PM) transitions. When the PM subsystem starts freezing user space processes, the wait_event_interruptible_timeout() is aborted early, which allows the unbind thread to proceed and nullify the gadget pointer (cdev->gadget = NULL): [ 814.123447][ T947] configfs-gadget.g1 gadget.0: uvc: uvc_function_unbind() [ 814.178583][ T3173] PM: suspend entry (deep) [ 814.192487][ T3173] Freezing user space processes [ 814.197668][ T947] configfs-gadget.g1 gadget.0: uvc: uvc_function_unbind no clean disconnect, wait for release When the PM subsystem resumes or aborts the suspend and tasks are restarted, the V4L2 release path is executed and attempts to access the already nullified gadget pointer, triggering a kernel panic: [ 814.292597][ C0] PM: pm_system_irq_wakeup: 479 triggered dhdpcie_host_wake [ 814.386727][ T3173] Restarting tasks ... [ 814.403522][ T4558] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000030 [ 814.404021][ T4558] pc : usb_gadget_deactivate+0x14/0xf4 [ 814.404031][ T4558] lr : usb_function_deactivate+0x54/0x94 [ 814.404078][ T4558] Call trace: [ 814.404080][ T4558] usb_gadget_deactivate+0x14/0xf4 [ 814.404083][ T4558] usb_function_deactivate+0x54/0x94 [ 814.404087][ T4558] uvc_function_disconnect+0x1c/0x5c [ 814.404092][ T4558] uvc_v4l2_release+0x44/0xac [ 814.404095][ T4558] v4l2_release+0xcc/0x130 Address the race condition and NULL pointer dereference by: 1. State Synchronization (flag + mutex) Introduce a 'func_unbound' flag in struct uvc_device. This allows uvc_function_disconnect() to safely skip accessing the nullified cdev->gadget pointer. As suggested by Alan Stern, this flag is protected by a new mutex (uvc->lock) to ensure proper memory ordering and prevent instruction reordering or speculative loads. This mutex is also used to protect 'func_connected' for consistent state management. 2. Explicit Synchronization (completion) Use a completion to synchronize uvc_function_unbind() with the uvc_vdev_release() callback. This prevents Use-After-Free (UAF) by ensuring struct uvc_device is freed after all video device resources are released.

Published
May 1, 2026
Updated
Nov 11, 2026
EPSS
0.1% · 1th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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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.

VendorProduct
linuxlinux kernel

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

    • e10735ce87502b07e171727e574afdd6c0890a08, 5.18affected
    • 1444e0568bc2c70868e7b8da5b46fc2252acc3f5 and later · before 0c00ec409d7b2bce3fcac73188b79a141db7cfdaaffected · git
    • 4962e5a2f301d24953f17d6748d986e21566abe1 and later · before d92d1532e05b1b31d36d48765e43bf73d793d19faffected · git
    • b81ac4395bbeaf36e078dea1a48c02dd97b76235 and later · before 0587de744615628c38e33ddc1601160a5ea8c50aaffected · git
    • b81ac4395bbeaf36e078dea1a48c02dd97b76235 and later · before c78e463ee134b4669579d453c81ae00795e4c19aaffected · git
    • b81ac4395bbeaf36e078dea1a48c02dd97b76235 and later · before 8a1128d604c360eca135f15b882b70256a522145affected · git
    • b81ac4395bbeaf36e078dea1a48c02dd97b76235 and later · before 1aa9356881ee4ed414bf72d0c56d915492cb5345affected · git
    • b81ac4395bbeaf36e078dea1a48c02dd97b76235 and later · before c038ba56b92e410d1caec22b2dc68780a0b42091affected · git
    • b81ac4395bbeaf36e078dea1a48c02dd97b76235 and later · before eba2936bbe6b752a31725a9eb5c674ecbf21ee7daffected · git
    • 5.10.117 and later · before 5.10.253affected · semver
Affected versions · NVD (8)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.10.117 and later · before 5.10.253
  • linux linux kernel5.15.41 and later · before 5.15.203
  • linux linux kernel5.18 and later · before 6.1.168
  • linux linux kernel6.2 and later · before 6.6.134
  • linux linux kernel6.7 and later · before 6.12.81
  • linux linux kernel6.13 and later · before 6.18.22
  • linux linux kernel6.19 and later · before 6.19.12
  • linux linux kernel7.0

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.12-16.19.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-31724May 1, 2026 · usb: gadget: f_eem: Fix net_device lifecycle with device_move
    22Monitor
  • ← EarlierCVE-2026-31725May 1, 2026 · usb: gadget: f_ecm: Fix net_device lifecycle with device_move
    22Monitor
  • Later →CVE-2026-31727May 1, 2026 · usb: gadget: u_ether: Fix NULL pointer deref in eth_get_drvinfo
    22Monitor

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 Linux0587de744615628c38e33ddc1601160a5ea8c50aVendor (CNA)
Linux Linux0c00ec409d7b2bce3fcac73188b79a141db7cfdaVendor (CNA)
Linux Linux1aa9356881ee4ed414bf72d0c56d915492cb5345Vendor (CNA)
Linux Linux5.10.253Vendor (CNA)
Linux Linux5.15.203Vendor (CNA)
Linux Linux5.18Vendor (CNA)
Linux Linux8a1128d604c360eca135f15b882b70256a522145Vendor (CNA)
Linux Linuxc038ba56b92e410d1caec22b2dc68780a0b42091Vendor (CNA)
Linux Linuxc78e463ee134b4669579d453c81ae00795e4c19aVendor (CNA)
Linux Linuxd92d1532e05b1b31d36d48765e43bf73d793d19fVendor (CNA)
Linux Linuxeba2936bbe6b752a31725a9eb5c674ecbf21ee7dVendor (CNA)
debian:linux6.1.170-1 · 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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

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

nvd-primary

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.

References

Show all references (7 more)

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

All records