{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74475", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.903Z", "datePublished": "2026-08-15T12:27:10.685Z", "dateUpdated": "2026-08-17T05:47:36.362Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:47:36.362Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use neigh_ha_snapshot() in route_shortcircuit()\n\nThe neighbour hardware address n->ha can be updated asynchronously by the\nneighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without\nholding the seqlock loop can lead to torn reads or reading a partially updated\nMAC address.\n\nUse neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under\nread_seqbegin()/read_seqretry() lock protection before using it.\n\nNote that arp_reduce() and neigh_reduce() seem to have the same issue\nleft for future patches."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L", "baseScore": 10, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - route_shortcircuit() runs on the vxlan_xmit() transmit path when overlay IP/IPv6 traffic is encapsulated; in cloud/SDN VTEP deployments a remote tenant can drive dev_queue_xmit() through bridge/IP forwarding without any local syscall or netlink access.\nAC:L - The attacker controls both sides of the race by concurrently sending overlay traffic that hits route_shortcircuit() and generating neighbour ha updates (ARP/NDP churn); repeated attempts do not depend on victim state or uncontrollable memory layout.\nPR:N - Exploitation requires only the ability to send overlay/underlay packets to a VTEP that already has VXLAN_F_RSC and router FDB entries configured by infrastructure; no CAP_NET_ADMIN, root, or host credentials are needed on the victim.\nUI:N - Triggering is automatic during kernel packet forwarding and VXLAN encapsulation once matching traffic flows; no mount, file open, or other victim action is required beyond normal overlay operation.\nS:C - A torn n->ha read can rewrite the skb Ethernet destination and reselect a different FDB remote, mis-encapsulating traffic to an unintended VXLAN peer and crossing intended multi-tenant overlay segmentation boundaries beyond the local VTEP authority.\nC:H - Unsynchronized reads of neighbour ha during concurrent updates yield torn MAC values that drive post-rewrite FDB lookup and encapsulation, potentially delivering other tenants' overlay frames to an attacker-controlled remote endpoint or leaking mixed neighbour state.\nI:H - The corrupted hardware address is copied into the skb Ethernet header and steers subsequent vxlan_find_mac_tx()/vxlan_xmit_one() encapsulation, enabling deterministic overlay traffic redirection or injection toward an attacker-chosen VTEP rather than the intended router destination.\nA:L - While the host kernel does not panic, torn MAC rewriting can cause mis-encapsulation, FDB misses, and dropped or misdelivered overlay packets, producing intermittent connectivity loss and performance degradation on affected VTEP nodes under sustained attack."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/vxlan/vxlan_core.c"], "versions": [{"version": "e4f67addf158f98f8197e08974966b18480dc751", "lessThan": "d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0", "status": "affected", "versionType": "git"}, {"version": "e4f67addf158f98f8197e08974966b18480dc751", "lessThan": "ec341bb76d77b4c2948764375ee6bfeef4bb41c3", "status": "affected", "versionType": "git"}, {"version": "e4f67addf158f98f8197e08974966b18480dc751", "lessThan": "ff89415d34c3ab9f5312316423122e664ed3524f", "status": "affected", "versionType": "git"}, {"version": "e4f67addf158f98f8197e08974966b18480dc751", "lessThan": "05f2987f73daa05333fd713d05546142f9f7c5f0", "status": "affected", "versionType": "git"}, {"version": "e4f67addf158f98f8197e08974966b18480dc751", "lessThan": "8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/vxlan/vxlan_core.c"], "versions": [{"version": "3.8", "status": "affected"}, {"version": "0", "lessThan": "3.8", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.8", "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": "3.8", "versionEndExcluding": "6.6.151"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.12.103"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.18.44"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "7.1.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0"}, {"url": "https://git.kernel.org/stable/c/ec341bb76d77b4c2948764375ee6bfeef4bb41c3"}, {"url": "https://git.kernel.org/stable/c/ff89415d34c3ab9f5312316423122e664ed3524f"}, {"url": "https://git.kernel.org/stable/c/05f2987f73daa05333fd713d05546142f9f7c5f0"}, {"url": "https://git.kernel.org/stable/c/8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d"}], "title": "vxlan: use neigh_ha_snapshot() in route_shortcircuit()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/net/vxlan/vxlan_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0", "status": "affected", "version": "e4f67addf158f98f8197e08974966b18480dc751", "versionType": "git"}, {"lessThan": "ec341bb76d77b4c2948764375ee6bfeef4bb41c3", "status": "affected", "version": "e4f67addf158f98f8197e08974966b18480dc751", "versionType": "git"}, {"lessThan": "ff89415d34c3ab9f5312316423122e664ed3524f", "status": "affected", "version": "e4f67addf158f98f8197e08974966b18480dc751", "versionType": "git"}, {"lessThan": "05f2987f73daa05333fd713d05546142f9f7c5f0", "status": "affected", "version": "e4f67addf158f98f8197e08974966b18480dc751", "versionType": "git"}, {"lessThan": "8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d", "status": "affected", "version": "e4f67addf158f98f8197e08974966b18480dc751", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/net/vxlan/vxlan_core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "3.8"}, {"lessThan": "3.8", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.151", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.103", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.44", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.8", "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\nvxlan: use neigh_ha_snapshot() in route_shortcircuit()\n\nThe neighbour hardware address n->ha can be updated asynchronously by the\nneighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without\nholding the seqlock loop can lead to torn reads or reading a partially updated\nMAC address.\n\nUse neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under\nread_seqbegin()/read_seqretry() lock protection before using it.\n\nNote that arp_reduce() and neigh_reduce() seem to have the same issue\nleft for future patches."}], "id": "CVE-2026-74475", "lastModified": "2026-08-17T06:19:43.543", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 10.0, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 6.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-15T13:17:52.293", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/05f2987f73daa05333fd713d05546142f9f7c5f0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ec341bb76d77b4c2948764375ee6bfeef4bb41c3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ff89415d34c3ab9f5312316423122e664ed3524f"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}