CVE-2026-64540usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup()
- 8.1HighCVSS base score
- 0.27%Exploitation in 30 daysEPSS · top 80% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
- 8 days later
· 8 days later
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High8.1 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.27% · top 80% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 255d03551f94c7bdd86c7d9181a70b21917d829f
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 4359376e6238d89977a35086e47ca3b07f43e850
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 8624e179fa3ce23c2fbd1a198ce30764b73f054a
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 573418f7ea8f859a841417eb4b915594094fd967
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 0575599e451aff3c5329922562374a2cab25fc51
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 3ef79fa3860e644c8de7834fa7300e1c58f38862
- affected 47ee3051c856cc2aa95d35d577a8cb37279d540f – < 8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a
- affected 2.6.14
- unaffected < 2.6.14
- unaffected 5.10.261 – ≤ 5.10.*
- unaffected 5.15.212 – ≤ 5.15.*
- unaffected 6.1.178 – ≤ 6.1.*
- unaffected 6.6.145 – ≤ 6.6.*
- unaffected 6.12.97 – ≤ 6.12.*
- unaffected 6.18.40 – ≤ 6.18.*
- unaffected 7.1.5 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References8
- https://git.kernel.org/stable/c/255d03551f94c7bdd86c7d9181a70b21917d829f (opens in a new tab)
- https://git.kernel.org/stable/c/4359376e6238d89977a35086e47ca3b07f43e850 (opens in a new tab)
- https://git.kernel.org/stable/c/8624e179fa3ce23c2fbd1a198ce30764b73f054a (opens in a new tab)
- https://git.kernel.org/stable/c/573418f7ea8f859a841417eb4b915594094fd967 (opens in a new tab)
- https://git.kernel.org/stable/c/0575599e451aff3c5329922562374a2cab25fc51 (opens in a new tab)
- https://git.kernel.org/stable/c/0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db (opens in a new tab)
- https://git.kernel.org/stable/c/3ef79fa3860e644c8de7834fa7300e1c58f38862 (opens in a new tab)
- https://git.kernel.org/stable/c/8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-49591 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64540)Record last updated .