SEPTEMBER 19, 2026
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Case File

CVE-2026-74701

HIGH · CVSS 7.8 EPSS 0.13%

Source: NVD + CISA KEV + EPSS · Published 2026-08-22 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

The vulnerability in the Linux kernel affects the Open vSwitch component, specifically in the handling of Ethernet headers during packet processing on ARPHRD_NONE devices, such as TUN. An attacker could exploit this flaw to trigger a kernel bug, potentially leading to a denial of service due to improper memory access when the packet's linear data is insufficient. Organizations utilizing Linux systems with Open vSwitch should prioritize patching this vulnerability to mitigate the risk of system instability.

CVE
CVE-2026-74701
Severity
HIGH
CVSS
7.8
EPSS
0.13%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: net/openvswitch: check Ethernet header length in key_extract() When a packet arrives on an ARPHRD_NONE device (e.g. TUN), ovs_flow_key_extract() trusts the user-provided skb->protocol field: if it is ETH_P_TEB, the packet is classified as MAC_PROTO_ETHERNET and key_extract() is called without ensuring the skb has ETH_HLEN (14) bytes of linear data. key_extract() unconditionally pulls 2 * ETH_ALEN bytes for MAC addresses and parse_ethertype() pulls 2 more, either of which triggers a kernel BUG in __skb_pull() when the linear area is too small. kernel BUG at include/linux/skbuff.h:2848! RIP: 0010:key_extract+0xa7e/0xd90 net/openvswitch/flow.c:933 ovs_flow_key_extract+0x419/0xa70 ovs_vport_receive+0x222/0x390 netdev_frame_hook+0x3e0/0x630 tun_get_user+0x2d0c/0x38e0 Fixed by calling check_header() in key_extract() before accessing the Ethernet header.