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High 8.1Published Jul 27, 2026

CVE-2026-64540usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup()

Updated under an hour ago ()

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It affects Linux. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

In the Linux kernel, the following vulnerability has been resolved: usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup() genelink_rx_fixup() splits an aggregated RX frame into its individual packets, using a per-packet length taken from device-supplied data. That length is only bounded by GL_MAX_PACKET_LEN (1514); it is never compared against how many bytes were actually received. A malicious GeneLink (GL620A) device can therefore send a short URB whose header claims packet_count > 1 and a first packet of up to 1514 bytes. skb_put_data(gl_skb, packet->packet_data, size); then copies past the end of the receive buffer and hands the adjacent slab contents up the network stack, an out-of-bounds read that leaks kernel heap. No privilege is required: the path runs in the usbnet RX softirq as soon as the interface is up. BUG: KASAN: slab-out-of-bounds in genelink_rx_fixup (drivers/net/usb/gl620a.c:112) Read of size 1514 at addr ffff888011309708 by task ksoftirqd/0/14 Call Trace: ... __asan_memcpy (mm/kasan/shadow.c:105) genelink_rx_fixup (include/linux/skbuff.h:2814 drivers/net/usb/gl620a.c:112) usbnet_bh (drivers/net/usb/usbnet.c:572 drivers/net/usb/usbnet.c:1589) process_one_work (kernel/workqueue.c:3322) bh_worker (kernel/workqueue.c:3405) tasklet_action (kernel/softirq.c:965) handle_softirqs (kernel/softirq.c:622) run_ksoftirqd (kernel/softirq.c:1076) ... skb_pull() already verifies that the requested length fits the buffer and returns NULL otherwise. Move it ahead of the copy and check its result, so a packet that overruns the received data is rejected before it is read. Well-formed frames, whose packets are fully present, are unaffected.

CVSS
8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weakness (CWE)
Not given
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Linux
NVD analysis
Received
Record last updated
Oct 16, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Linux Linux
linux:linux (from the name)
from 47ee3051c856cc2aa95d35d577a8cb37279d540f before 255d03551f94c7bdd86c7d9181a70b21917d829f; from 47ee3051c856cc2aa95d35d577a8cb37279d540f before 4359376e6238d89977a35086e47ca3b07f43e850; from 47ee3051c856cc2aa95d35d577a8cb37279d540f before 8624e179fa3ce23c2fbd1a198ce30764b73f054a; from 47ee3051c856cc2aa95d35d577a8cb37279d540f before 573418f7ea8f859a841417eb4b915594094fd967; from 47ee3051c856cc2aa95d35d577a8cb37279d540f before 0575599e451aff3c5329922562374a2cab25fc51; 47ee3051c856cc2aa95d35d577a8cb37279d540f builds before 0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db; 47ee3051c856cc2aa95d35d577a8cb37279d540f builds before 3ef79fa3860e644c8de7834fa7300e1c58f38862; 47ee3051c856cc2aa95d35d577a8cb37279d540f builds before 8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a
CNA record

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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