net/openvswitch: check Ethernet header length in key_extract()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45, 7.1.9, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-74701
- 2026-10-03 Alias added: GHSA-6727-4wmg-w3rc
- 2026-10-18 CISA SSVC decision points changed
References
Other 8
- https://git.kernel.org/stable/c/e85278afd4890dd190ba3c7a1b1a712b801c9fe1
- https://git.kernel.org/stable/c/81f9b09f0ea3ba9ab966dd17e9f32625a14555e9
- https://git.kernel.org/stable/c/831471718f6e19aed1a330b03b53190a90e06466
- https://git.kernel.org/stable/c/d8bea341b183190ce6c055ab0e64ab78eb9a7290
- https://git.kernel.org/stable/c/0b60b55652ba772b173dddc63f3851e1d2dd5927
- https://git.kernel.org/stable/c/a8139285c8925efe59af28a9169bb2fda91bff15
- https://git.kernel.org/stable/c/9b8cfbb58b85bfa7a78fac47fdc77396cd01f699
- https://git.kernel.org/stable/c/cf6f8b29befb92173659bcef6a441d274947bfae
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- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-74701 · CVE Program
- CVE-2026-74701 · NVD
- FIRST EPSS
- GHSA-6727-4wmg-w3rc · GitHub Advisory Database · CC BY 4.0
- CVE-2026-74701 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences