{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72248", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.914Z", "datePublished": "2026-08-15T05:54:36.535Z", "dateUpdated": "2026-08-17T05:41:59.975Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:41:59.975Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable: support IPIP tunnel with direct xmit\n\nThe combination of IPIP tunnel with direct xmit, eg. bridge device,\nbreaks because no dst_entry is provided to check the skb headroom and to\nset the iph->frag_off field. This leads to invalid dst usage and can\ntrigger a crash in the tunnel transmit path.\n\nFix this by moving dst_cache and dst_cookie out of the runtime union so\nthat they can be shared by neighbour, xfrm, and direct tunnel flows.\nFor FLOW_OFFLOAD_XMIT_DIRECT tuples carrying tunnel metadata, preserve\nroute state in these shared fields and release it through the common\ndst release path.\n\nSince dst_entry is now available to the three supported xmit modes and\ndst_release() already deals with NULL dst, remove the xmit type check\nin nft_flow_dst_release(). Moreover, skip the check if the dst entry\nis NULL in nf_flow_dst_check() which is now the case for the direct\nxmit case.\n\nBased on patch from Rein Wei <n05ec@lzu.edu.cn>."}], "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 bug is hit in the netfilter flowtable ingress fast path when remotely sourced TCP/UDP packets matching an offloaded flow are received on flowtable-bound interfaces, not via netlink configuration APIs.\nAC:L - An attacker can reliably establish the offloaded flow by sending matching traffic and then repeatedly trigger the faulty IPIP direct-xmit tunnel push on subsequent packets without depending on uncontrollable timing or memory layout.\nPR:N - Exploitation requires only the ability to send network traffic through an already deployed IPIP-through-bridge flowtable offload path; no local account, authentication, or CAP_NET_ADMIN on the target is needed to trigger the crash.\nUI:N - No victim interaction is required beyond normal network traffic delivery; the attacker does not need the user to open files, mount filesystems, or perform any deliberate action.\nS:U - Impact is confined to kernel memory corruption and denial of service on the affected network namespace/host; it does not cross a VM, container, or IOMMU security boundary to compromise a separate authority.\nC:H - FLOW_OFFLOAD_XMIT_DIRECT stores MAC/ifindex data in a union aliasing dst_cache, so nf_flow_tunnel_ipip_push dereferences attacker-influenced bytes as a dst_entry/rtable, enabling uncontrolled kernel memory reads before the fault.\nI:H - The same invalid dst pointer drives skb_cow_head/headroom calculations and tunnel header writes in kernel transmit context, giving a plausible path to heap corruption and control-flow disruption beyond a simple NULL dereference.\nA:H - Invalid dst usage in the IPIP tunnel transmit path can cause kernel oops/panic or hard lockup when offloaded flows are exercised, fully denying availability of the affected system."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/netfilter/nf_flow_table.h", "net/netfilter/nf_flow_table_core.c", "net/netfilter/nf_flow_table_ip.c"], "versions": [{"version": "d30301ba4b07ac92eb38353a111833b009003170", "lessThan": "0880c4ed122d0cddc9f29a2b28f055d1f24f0fca", "status": "affected", "versionType": "git"}, {"version": "d30301ba4b07ac92eb38353a111833b009003170", "lessThan": "fa7395c02d95e51bad2952325d2d6503bfbad437", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/netfilter/nf_flow_table.h", "net/netfilter/nf_flow_table_core.c", "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/0880c4ed122d0cddc9f29a2b28f055d1f24f0fca"}, {"url": "https://git.kernel.org/stable/c/fa7395c02d95e51bad2952325d2d6503bfbad437"}], "title": "netfilter: flowtable: support IPIP tunnel with direct xmit", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/net/netfilter/nf_flow_table.h", "net/netfilter/nf_flow_table_core.c", "net/netfilter/nf_flow_table_ip.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "0880c4ed122d0cddc9f29a2b28f055d1f24f0fca", "status": "affected", "version": "d30301ba4b07ac92eb38353a111833b009003170", "versionType": "git"}, {"lessThan": "fa7395c02d95e51bad2952325d2d6503bfbad437", "status": "affected", "version": "d30301ba4b07ac92eb38353a111833b009003170", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/net/netfilter/nf_flow_table.h", "net/netfilter/nf_flow_table_core.c", "net/netfilter/nf_flow_table_ip.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.19"}, {"lessThan": "6.19", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable: support IPIP tunnel with direct xmit\n\nThe combination of IPIP tunnel with direct xmit, eg. bridge device,\nbreaks because no dst_entry is provided to check the skb headroom and to\nset the iph->frag_off field. This leads to invalid dst usage and can\ntrigger a crash in the tunnel transmit path.\n\nFix this by moving dst_cache and dst_cookie out of the runtime union so\nthat they can be shared by neighbour, xfrm, and direct tunnel flows.\nFor FLOW_OFFLOAD_XMIT_DIRECT tuples carrying tunnel metadata, preserve\nroute state in these shared fields and release it through the common\ndst release path.\n\nSince dst_entry is now available to the three supported xmit modes and\ndst_release() already deals with NULL dst, remove the xmit type check\nin nft_flow_dst_release(). Moreover, skip the check if the dst entry\nis NULL in nf_flow_dst_check() which is now the case for the direct\nxmit case.\n\nBased on patch from Rein Wei <n05ec@lzu.edu.cn>."}], "id": "CVE-2026-72248", "lastModified": "2026-08-17T06:18:26.757", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-15T06:21:52.030", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0880c4ed122d0cddc9f29a2b28f055d1f24f0fca"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fa7395c02d95e51bad2952325d2d6503bfbad437"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: netfilter: flowtable: support IPIP tunnel with direct xmit", "id": "2516255", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516255"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-824", "details": ["A flaw was found in the Linux kernel's netfilter flowtable component. When an Internet Protocol over Internet Protocol (IPIP) tunnel is used with direct transmit (xmit), such as with a bridge device, the system fails to properly handle network packet destination entries. This improper handling can lead to a system crash in the tunnel transmit path, resulting in a Denial of Service (DoS)."], "name": "CVE-2026-72248", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-72248\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-72248\nhttps://lore.kernel.org/linux-cve-announce/2026081552-CVE-2026-72248-7cf5@gregkh/T"], "threat_severity": "Important"}