CVE-2026-74701

net/openvswitch: check Ethernet header length in key_extract()

State: Published
Severity: 7.8 High
Published: Aug 22, 2026
Updated: Oct 16, 2026
Reserved: Aug 15, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	217ac77a3c2524d999730b2a80b61fcc2d0f734a to before e85278afd4890dd190ba3c7a1b1a712b801c9fe1Affected 217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 81f9b09f0ea3ba9ab966dd17e9f32625a14555e9Affected 217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 831471718f6e19aed1a330b03b53190a90e06466Affected 217ac77a3c2524d999730b2a80b61fcc2d0f734a to before d8bea341b183190ce6c055ab0e64ab78eb9a7290Affected 217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 0b60b55652ba772b173dddc63f3851e1d2dd5927Affected 217ac77a3c2524d999730b2a80b61fcc2d0f734a to before a8139285c8925efe59af28a9169bb2fda91bff15Affected 217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 9b8cfbb58b85bfa7a78fac47fdc77396cd01f699Affected 217ac77a3c2524d999730b2a80b61fcc2d0f734a to before cf6f8b29befb92173659bcef6a441d274947bfaeAffected
LinuxLinux	4.10Affected before 4.10Not affected 5.10.265 through 5.10.Not affected 5.15.216 through 5.15.Not affected 6.1.183 through 6.1.Not affected 6.6.152 through 6.6.Not affected 6.12.104 through 6.12.Not affected 6.18.45 through 6.18.Not affected 7.1.9 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

217ac77a3c2524d999730b2a80b61fcc2d0f734a to before e85278afd4890dd190ba3c7a1b1a712b801c9fe1Affected
217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 81f9b09f0ea3ba9ab966dd17e9f32625a14555e9Affected
217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 831471718f6e19aed1a330b03b53190a90e06466Affected
217ac77a3c2524d999730b2a80b61fcc2d0f734a to before d8bea341b183190ce6c055ab0e64ab78eb9a7290Affected
217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 0b60b55652ba772b173dddc63f3851e1d2dd5927Affected
217ac77a3c2524d999730b2a80b61fcc2d0f734a to before a8139285c8925efe59af28a9169bb2fda91bff15Affected
217ac77a3c2524d999730b2a80b61fcc2d0f734a to before 9b8cfbb58b85bfa7a78fac47fdc77396cd01f699Affected
217ac77a3c2524d999730b2a80b61fcc2d0f734a to before cf6f8b29befb92173659bcef6a441d274947bfaeAffected

LinuxLinux

4.10Affected
before 4.10Not affected
5.10.265 through 5.10.*Not affected
5.15.216 through 5.15.*Not affected
6.1.183 through 6.1.*Not affected
6.6.152 through 6.6.*Not affected
6.12.104 through 6.12.*Not affected
6.18.45 through 6.18.*Not affected
7.1.9 through 7.1.*Not affected
7.2 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.