CVE-2026-80824: Linux kernel · usb: usbfs: fix use-after-free of usb_device in usbdev_release()
Source GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 4 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: usb: usbfs: fix use-after-free of usb_device in usbdev_release() usbdev_release() drops its reference to the struct usb_device before draining the list of completed async URBs, but that drain path reads back through the same object: free_async() calls dec_usb_memory_use_count() for any URB whose buffer came from the usbfs mmap() region, and its first statement is bus_to_hcd(ps->dev->bus). After a disconnect the usbfs reference can be the last one, in which case usb_put_dev() frees the device and the subsequent loop reads offset 80 of freed memory and uses the result as a struct usb_hcd *, which hcd_buffer_free_pages() then dereferences. This is reachable by an unprivileged process that has read/write access to a /dev/bus/usb node: mmap() the fd, submit one URB with a buffer inside the mapping, wait for the device to be unplugged, then munmap() and close(). It reproduces on every attempt rather than being a race, because a live MAP_SHARED vma holds a reference on the struct file, so usbdev_release() cannot run until the last vma is gone and the freeing branch of dec_usb_memory_use_count() is always taken. BUG: KASAN: slab-use-after-free in dec_usb_memory_use_count+0x3ae/0x410 Read of size 8 at addr ffff8880122ee050 by task poc/769 CPU: 1 UID: 1000 PID: 769 Comm: poc Tainted: G B 6.12.94 #3 Call Trace: dec_usb_memory_use_count+0x3ae/0x410 free_async+0x2aa/0x4f0 usbdev_release+0x375/0x460 __fput+0x3ea/0xb50 __x64_sys_close+0x86/0x100 Allocated by task 11: usb_alloc_dev+0x55/0xd90 hub_event+0x2524/0x43d0 Freed by task 769: kfree+0x121/0x360 device_release+0xd2/0x280 usb_put_dev+0x23/0x30 usbdev_release+0x2d8/0x460 Release the device reference after the drain loop instead. Nothing between the two points requires it to have been dropped.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80824 (opens in a new tab)
- git.kernel.org/stable/c/0a960b88c5979f853019d4dc4957dfbeeb193440 (opens in a new tab)
- git.kernel.org/stable/c/0dd68b5d01d022fc9c5e71c82a82b0a94d3d0671 (opens in a new tab)
- git.kernel.org/stable/c/47a7f98fbb5006d46d15a3a210ffdc61448a4f19 (opens in a new tab)
- git.kernel.org/stable/c/5f08c45bdcfd28d1171de38c5ef29fc89a76eedc (opens in a new tab)
- git.kernel.org/stable/c/65879e0a452ca2a234b9475e0c11aff7a4343738 (opens in a new tab)
- git.kernel.org/stable/c/7f0278e474c4d1c4457974ff1137cc385c944ab3 (opens in a new tab)
- git.kernel.org/stable/c/96f5520fc9a5e4bbf77ac93c9d5ce502f597e6cf (opens in a new tab)
- git.kernel.org/stable/c/b3cde26a66b04f1d90ed0b675899c88b4e49d424 (opens in a new tab)
- git.kernel.org/stable/c/bd4bffc621a8cb2f4d9ed9b6447415de524a3bef (opens in a new tab)