{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74701", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.927Z", "datePublished": "2026-08-22T15:33:01.585Z", "dateUpdated": "2026-10-16T19:16:10.294Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:41:43.778Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/openvswitch: check Ethernet header length in key_extract()\n\nWhen a packet arrives on an ARPHRD_NONE device (e.g. TUN),\novs_flow_key_extract() trusts the user-provided skb->protocol field: if\nit is ETH_P_TEB, the packet is classified as MAC_PROTO_ETHERNET and\nkey_extract() is called without ensuring the skb has ETH_HLEN (14) bytes\nof linear data. key_extract() unconditionally pulls 2 * ETH_ALEN bytes\nfor MAC addresses and parse_ethertype() pulls 2 more, either of which\ntriggers a kernel BUG in __skb_pull() when the linear area is too small.\n\n kernel BUG at include/linux/skbuff.h:2848!\n RIP: 0010:key_extract+0xa7e/0xd90 net/openvswitch/flow.c:933\n ovs_flow_key_extract+0x419/0xa70\n ovs_vport_receive+0x222/0x390\n netdev_frame_hook+0x3e0/0x630\n tun_get_user+0x2d0c/0x38e0\n\nFixed by calling check_header() in key_extract() before accessing the\nEthernet header." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The crash is reached when a crafted skb is processed in ovs_flow_key_extract() via ovs_vport_receive(); the documented reproducer injects it through tun_get_user() (write to a TUN fd), and the alternate path is OVS_PACKET_CMD_EXECUTE netlink—both require local syscall access, not remote packet delivery.\nAC:L - The attacker fully controls skb length, skb->protocol (ETH_P_TEB), and linear versus fragmented layout; sending a sub-14-byte payload with ETH_P_TEB on an ARPHRD_NONE OVS port deterministically reaches key_extract() and triggers __skb_pull() BUG() without races or special heap layout.\nPR:L - Attaching an ARPHRD_NONE netdev to an OVS datapath and using OVS_PACKET_CMD_EXECUTE require CAP_NET_ADMIN (GENL_UNS_ADMIN_PERM, netnsok); CAP_NET_ADMIN is obtainable inside an unprivileged user+network namespace, and TUN injection likewise requires CAP_NET_ADMIN or a TUN fd granted by a privileged setup.\nUI:N - No victim interaction is required; once OVS bridges an ARPHRD_NONE port (e.g. TUN), the attacker triggers the bug by injecting a single malformed packet via write() or netlink without any other user action.\nS:U - Impact is a kernel BUG/panic in the same kernel security authority as the attacker; this is not a VM escape, IOMMU bypass, or cross-namespace privilege boundary crossing.\nC:H - Before the BUG, key_extract() calls ether_addr_copy() and parse_ethertype() on skb->data without validating ETH_HLEN, performing out-of-bounds reads of kernel skb buffer memory beyond the actual packet payload.\nI:H - Unchecked __skb_pull() on an undersized skb corrupts skb->data and skb->len metadata; this memory corruption of kernel packet state can be leveraged for further integrity violations beyond a simple controlled crash.\nA:H - The flaw triggers kernel BUG() at __skb_pull() in include/linux/skbuff.h, producing a kernel oops/panic and denying all system availability on affected hosts running Open vSwitch with ARPHRD_NONE ports." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/openvswitch/flow.c" ], "versions": [ { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "e85278afd4890dd190ba3c7a1b1a712b801c9fe1", "status": "affected", "versionType": "git" }, { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "81f9b09f0ea3ba9ab966dd17e9f32625a14555e9", "status": "affected", "versionType": "git" }, { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "831471718f6e19aed1a330b03b53190a90e06466", "status": "affected", "versionType": "git" }, { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "d8bea341b183190ce6c055ab0e64ab78eb9a7290", "status": "affected", "versionType": "git" }, { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "0b60b55652ba772b173dddc63f3851e1d2dd5927", "status": "affected", "versionType": "git" }, { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "a8139285c8925efe59af28a9169bb2fda91bff15", "status": "affected", "versionType": "git" }, { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "9b8cfbb58b85bfa7a78fac47fdc77396cd01f699", "status": "affected", "versionType": "git" }, { "version": "217ac77a3c2524d999730b2a80b61fcc2d0f734a", "lessThan": "cf6f8b29befb92173659bcef6a441d274947bfae", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/openvswitch/flow.c" ], "versions": [ { "version": "4.10", "status": "affected" }, { "version": "0", "lessThan": "4.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e85278afd4890dd190ba3c7a1b1a712b801c9fe1" }, { "url": "https://git.kernel.org/stable/c/81f9b09f0ea3ba9ab966dd17e9f32625a14555e9" }, { "url": "https://git.kernel.org/stable/c/831471718f6e19aed1a330b03b53190a90e06466" }, { "url": "https://git.kernel.org/stable/c/d8bea341b183190ce6c055ab0e64ab78eb9a7290" }, { "url": "https://git.kernel.org/stable/c/0b60b55652ba772b173dddc63f3851e1d2dd5927" }, { "url": "https://git.kernel.org/stable/c/a8139285c8925efe59af28a9169bb2fda91bff15" }, { "url": "https://git.kernel.org/stable/c/9b8cfbb58b85bfa7a78fac47fdc77396cd01f699" }, { "url": "https://git.kernel.org/stable/c/cf6f8b29befb92173659bcef6a441d274947bfae" } ], "title": "net/openvswitch: check Ethernet header length in key_extract()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74701", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:14:55.662820Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:16:10.294Z" } } ] } }