CyberSecBulletin
CVE-2026-64346NVD status: Analyzed

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-64346 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 50eeb8e8a4f389efc91b93cff14a683e714ec194, 7a5214dae906d9f58e07bc4995e8181ee74439f4, d026f71df141c9b064ff32a78af5391a31ef75c2 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.16% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 50eeb8e8a4f389efc91b93cff14a683e714ec194 or 7a5214dae906d9f58e07bc4995e8181ee74439f4 or d026f71df141c9b064ff32a78af5391a31ef75c2 or b52476a83d9e12df00765359d728a875b128bef1, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.178 or 6.6.145 or 6.12.96 or 6.18.39, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxfc274c1e997314bf47f6a62c79b5d7e554ed59c4 up to, but not including, 50eeb8e8a4f389efc91b93cff14a683e714ec194; fc274c1e997314bf47f6a62c79b5d7e554ed59c4 up to, but not including, 7a5214dae906d9f58e07bc4995e8181ee74439f4; fc274c1e997314bf47f6a62c79b5d7e554ed59c4 up to, but not including, d026f71df141c9b064ff32a78af5391a31ef75c2; fc274c1e997314bf47f6a62c79b5d7e554ed59c4 up to, but not including, b52476a83d9e12df00765359d728a875b128bef1; fc274c1e997314bf47f6a62c79b5d7e554ed59c4 up to, but not including, 54fa390aae393eb130f307a85562e3001cc39a52; fc274c1e997314bf47f6a62c79b5d7e554ed59c4 up to, but not including, 67e511d2989eb1c8c588b599ce2fcc6bb8e6f7ea; 5.1950eeb8e8a4f389efc91b93cff14a683e714ec194, 7a5214dae906d9f58e07bc4995e8181ee74439f4, d026f71df141c9b064ff32a78af5391a31ef75c2, b52476a83d9e12df00765359d728a875b128bef1, 54fa390aae393eb130f307a85562e3001cc39a52, 67e511d2989eb1c8c588b599ce2fcc6bb8e6f7ea
LinuxLinux Kernel5.19 up to, but not including, 6.1.178; 6.2 up to, but not including, 6.6.145; 6.7 up to, but not including, 6.12.96; 6.13 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4; 7.26.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: udc: Fix use-after-free in gadget_match_driver The udc structure acts as the management structure for the gadget, but their lifecycles are decoupled. A race condition exists where usb_del_gadget() frees the udc memory (e.g., via mode-switch work) while gadget_match_driver() concurrently accesses the freed udc memory (e.g., via configfs), causing a Use-After-Free (UAF) that triggers a NULL pointer dereference when the freed memory is zeroed: [39430.908615][ T1171] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [39430.911397][ T1171] pc : __pi_strcmp+0x20/0x140 [39430.911441][ T1171] lr : gadget_match_driver+0x34/0x60 ... [39430.911890][ T1171] usb_gadget_register_driver_owner+0x50/0xf8 [39430.911910][ T1171] gadget_dev_desc_UDC_store+0xf4/0x140 [39430.931308][ T1171] configfs_write_iter+0xec/0x134 [39430.957058][ T1171] Workqueue: events_freezable __dwc3_set_mode [39430.957287][ T1171] dwc3_gadget_exit+0x34/0x8c [39430.957304][ T1171] __dwc3_set_mode+0xc0/0x664 Fix this by ensuring the udc structure remains allocated until the gadget is released. To achieve this, introduce a new usb_gadget_release() routine to the core. When the gadget is added, usb_add_gadget() stores the gadget's release routine in the udc structure and takes a reference to the udc. When the gadget is released, usb_gadget_release() drops the reference to the udc and then calls the gadget's release routine.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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