CVE-2026-31728
MediumIn the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_ether: Fix race between gether_disconnect and eth_stop A race condition between gether_disconnect() and eth_stop() leads to a NULL pointer dereference. Specifically, if eth_stop() is triggered concurrently while gether_disconnect() is tearing down the endpoints, eth_stop() attempts to access the cleared endpoint descriptor, causing the following NPE: Unable to handle kernel NULL pointer dereference Call trace: __dwc3_gadget_ep_enable+0x60/0x788 dwc3_gadget_ep_enable+0x70/0xe4 usb_ep_enable+0x60/0x15c eth_stop+0xb8/0x108 Because eth_stop() crashes while holding the dev->lock, the thread running gether_disconnect() fails to acquire the same lock and spins forever, resulting in a hardlockup: Core - Debugging Information for Hardlockup core(7) Call trace: queued_spin_lock_slowpath+0x94/0x488 _raw_spin_lock+0x64/0x6c gether_disconnect+0x19c/0x1e8 ncm_set_alt+0x68/0x1a0 composite_setup+0x6a0/0xc50 The root cause is that the clearing of dev->port_usb in gether_disconnect() is delayed until the end of the function. Move the clearing of dev->port_usb to the very beginning of gether_disconnect() while holding dev->lock. This cuts off the link immediately, ensuring eth_stop() will see dev->port_usb as NULL and safely bail out.
CVSS 3.1 score
4.7
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-362CVE-2026-31728 is a Race Condition vulnerability
What is Race Condition?
The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE
Affected versions
Linux kernel versions
2.6.27
and later are affected. Fixed in
5.10.253,
5.15.203,
6.1.169,
6.6.134,
6.12.81,
6.18.22,
6.19.12,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-31728 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/6ad77458637b78ec655e3da5f112c862e6690a9d
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PatchKernel patch commithttps://git.kernel.org/stable/c/8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8
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PatchKernel patch commithttps://git.kernel.org/stable/c/a259ba0bce3b192c04334499690372a250f7d0b1
Frequently asked questions
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What is CVE-2026-31728?
CVE-2026-31728 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Race Condition flaw (CWE-362) . It affects Linux kernel versions from 2.6.27 onward and has been patched in 5.10.253, 5.15.203, 6.1.169 and others. CVE-2026-31728 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-31728?
CVE-2026-31728 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-31728?
Yes — CVE-2026-31728 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.169 and others. If you are running Linux kernel 2.6.27 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-31728 actively exploited?
No — CVE-2026-31728 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Race Condition (CWE-362)?
The product contains a code sequence that can run concurrently with other code, creating unexpected states. View CWE-362 on MITRE CWE →