{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72417", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.927Z", "datePublished": "2026-08-15T05:56:37.547Z", "dateUpdated": "2026-08-17T05:43:57.257Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:43:57.257Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable: Validate iph->ihl in nf_flow_ip4_tunnel_proto()\n\nAdd sanity check for iph->ihl field in nf_flow_ip4_tunnel_proto() before\nusing it to compute the header size, avoiding out-of-bounds access with\nmalformed IP headers.\nWhile at it, use iph->protocol instead of the hardcoded IPPROTO_IPIP\nconstant when setting ctx->tun.proto and reference ctx->tun.hdr_size\nwhen updating ctx->offset." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The flaw is hit in nf_flow_offload_ip_hook on NF_NETDEV_INGRESS for IPv4 packets arriving on nftables flowtable devices; a remote attacker can send crafted malformed IP/IPIP headers to that interface without any local access on the victim.\nAC:L - Once a flowtable ingress hook exists, the attacker fully controls packet headers and can reliably reach nf_flow_ip4_tunnel_proto() by sending IP traffic with an invalid ihl field; no race or victim-specific state beyond admin-enabled flow offload is required.\nPR:N - Exploitation requires no credentials or capabilities on the victim host—only that an administrator previously configured nftables flow offload on an ingress device; any remote sender can deliver the malformed packets to trigger parsing on the fast path.\nUI:N - No victim interaction is needed; malicious packets are processed automatically by the netdev ingress netfilter hook during normal receive/forward softirq handling on the configured interface.\nS:U - Impact is kernel memory corruption and crashes within the host kernel security boundary; this is standard in-kernel compromise territory, not a VM escape, IOMMU bypass, or other cross-authority scope change.\nC:H - Missing ihl validation lets iph->ihl<<2 compute an incorrect header size and ctx->offset, causing out-of-bounds skb reads in subsequent tuple parsing and forwarding; per kernel guidance, OOB reads warrant High confidentiality impact.\nI:H - Incorrect ctx->offset propagates into nf_flow_tuple_ip() and nf_flow_offload_forward(), which invoke skb_ensure_writable() and perform in-place NAT/header mutation at attacker-influenced offsets—memory corruption exploitable for write primitives warrants High integrity impact.\nA:H - Out-of-bounds access in softirq packet processing on the flowtable fast path can trigger KASAN reports, kernel oops, or panics when malformed headers are processed, constituting High availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_flow_table_ip.c" ], "versions": [ { "version": "ab427db17885814069bae891834f20842f0ac3a4", "lessThan": "025a41e76b51fbc7b8eaa5bacbaa9621d00e6aa7", "status": "affected", "versionType": "git" }, { "version": "ab427db17885814069bae891834f20842f0ac3a4", "lessThan": "84460b644329e25809b4a6d9279d6359d7fd8ebc", "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/netfilter/nf_flow_table_ip.c" ], "versions": [ { "version": "6.19", "status": "affected" }, { "version": "0", "lessThan": "6.19", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "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": "6.19", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/025a41e76b51fbc7b8eaa5bacbaa9621d00e6aa7" }, { "url": "https://git.kernel.org/stable/c/84460b644329e25809b4a6d9279d6359d7fd8ebc" } ], "title": "netfilter: flowtable: Validate iph->ihl in nf_flow_ip4_tunnel_proto()", "x_generator": { "engine": "bippy-1.2.0" } } } }