Linux Kernel up to 7.2-rc1 usbnet/gl620a drivers/net/usb/gl620a.c genelink_rx_fixup packet_data out-of-bounds

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.0	$0-$5k	0.00

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 7.2-rc1. The affected element is the function genelink_rx_fixup of the file drivers/net/usb/gl620a.c of the component usbnet/gl620a. The manipulation of the argument packet_data leads to out-of-bounds. This vulnerability is traded as CVE-2026-64540. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 7.2-rc1. This issue affects the function genelink_rx_fixup of the file drivers/net/usb/gl620a.c of the component usbnet/gl620a. The manipulation of the argument packet_data with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-64540 since 07/19/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/05/2026).

Upgrading to version 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5 or 7.2-rc2 eliminates this vulnerability. Applying the patch 255d03551f94c7bdd86c7d9181a70b21917d829f/4359376e6238d89977a35086e47ca3b07f43e850/8624e179fa3ce23c2fbd1a198ce30764b73f054a/573418f7ea8f859a841417eb4b915594094fd967/0575599e451aff3c5329922562374a2cab25fc51/0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db/3ef79fa3860e644c8de7834fa7300e1c58f38862/8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-2536). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.260
• 5.15.211
• 6.1.177
• 6.6.144
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
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• 6.12.90
• 6.12.91
• 6.12.92
• 6.12.93
• 6.12.94
• 6.12.95
• 6.12.96
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
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• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.2-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.261/5.15.212/6.1.178/6.6.145/6.12.97/6.18.40/7.1.5/7.2-rc2
Patch: 255d03551f94c7bdd86c7d9181a70b21917d829f/4359376e6238d89977a35086e47ca3b07f43e850/8624e179fa3ce23c2fbd1a198ce30764b73f054a/573418f7ea8f859a841417eb4b915594094fd967/0575599e451aff3c5329922562374a2cab25fc51/0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db/3ef79fa3860e644c8de7834fa7300e1c58f38862/8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a

Timelineinfo

07/19/2026 CVE reserved
07/27/2026 +8 days Advisory disclosed
07/27/2026 +0 days VulDB entry created
08/05/2026 +9 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64540 (🔒)
GCVE (CVE): GCVE-0-2026-64540
GCVE (VulDB): GCVE-100-383609
CERT Bund: WID-SEC-2026-2536 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 07/27/2026 23:28
Updated: 08/05/2026 14:42
Changes: 07/27/2026 23:28 (61), 08/05/2026 14:42 (7)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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