{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74406", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.892Z", "datePublished": "2026-08-15T05:59:15.385Z", "dateUpdated": "2026-08-17T05:46:49.365Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:46:49.365Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().\n\nudp_tunnel_sock_release() could set sk->sk_user_data to NULL\nwhile vxlan_gro_prepare_receive() is running.\n\nLet's check if rcu_dereference_sk_user_data() is NULL after\nskb_gro_remcsum_init()."}], "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 in vxlan_gro_prepare_receive() on the UDP GRO receive path; remote VXLAN/UDP packets reach it via inet_gro_receive\u2192udp4_gro_receive\u2192udp_tunnel_gro_rcv\u2192vxlan_gro_receive during NAPI processing on internet/cloud overlay endpoints.\nAC:L - An attacker can reliably trigger the race by flooding VXLAN GRO packets while concurrently tearing down the VXLAN device (e.g., via CAP_NET_ADMIN in a user namespace); repeated attempts during orchestrated interface churn also make the timing window attacker-driven rather than purely environmental.\nPR:N - Exploitation requires only the ability to send crafted VXLAN UDP traffic to a listening tunnel port; no target credentials or local account are needed, and concurrent teardown can occur from normal administrative or automation activity rather than attacker-held privileges.\nUI:N - No victim interaction is required beyond the host already running a VXLAN interface; the attacker triggers the fault purely by sending network packets timed against interface teardown.\nS:U - Impact is a kernel fault in networking softirq context on the same host; it does not cross VM, container, or IOMMU security boundaries into another authority.\nC:H - The race can leave a stale vxlan_sock pointer after udp_tunnel_sock_release() frees sk_user_data; dereferencing vs->flags is a use-after-free read that can expose kernel heap contents and is treated as arbitrary read potential under conservative scoring.\nI:H - Use-after-free on the vxlan_sock object during GRO teardown can corrupt heap metadata or adjacent objects and be leveraged for control-flow hijacking, not merely a benign NULL check failure.\nA:H - A successful trigger causes a kernel NULL pointer dereference/oops in NAPI/softirq context (documented crash at vxlan_gro_prepare_receive), typically crashing or hanging the host and denying all services."}]}], "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": "5602c48cf87562c2f95b831d690631935e834295", "lessThan": "9c58c729d32e7cea5772cc44929c6cd61e5a31cd", "status": "affected", "versionType": "git"}, {"version": "5602c48cf87562c2f95b831d690631935e834295", "lessThan": "f79c80f173fda9545b220c1f094b65fc06c252d0", "status": "affected", "versionType": "git"}, {"version": "5602c48cf87562c2f95b831d690631935e834295", "lessThan": "08f40c0d23c67c3aa4224c3311e134999c721fb4", "status": "affected", "versionType": "git"}, {"version": "5602c48cf87562c2f95b831d690631935e834295", "lessThan": "4a8cde6f7281ea2c4c290f9ad9923b3631defceb", "status": "affected", "versionType": "git"}, {"version": "5602c48cf87562c2f95b831d690631935e834295", "lessThan": "ef44dac2a37f86eeae6b88ed10a6d60b35387dfd", "status": "affected", "versionType": "git"}, {"version": "5602c48cf87562c2f95b831d690631935e834295", "lessThan": "30a45c0bffdd62350261e2f2689fdba426a33578", "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": "4.7", "status": "affected"}, {"version": "0", "lessThan": "4.7", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.40", "lessThanOrEqual": "6.18.*", "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": "4.7", "versionEndExcluding": "6.1.178"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.18.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/9c58c729d32e7cea5772cc44929c6cd61e5a31cd"}, {"url": "https://git.kernel.org/stable/c/f79c80f173fda9545b220c1f094b65fc06c252d0"}, {"url": "https://git.kernel.org/stable/c/08f40c0d23c67c3aa4224c3311e134999c721fb4"}, {"url": "https://git.kernel.org/stable/c/4a8cde6f7281ea2c4c290f9ad9923b3631defceb"}, {"url": "https://git.kernel.org/stable/c/ef44dac2a37f86eeae6b88ed10a6d60b35387dfd"}, {"url": "https://git.kernel.org/stable/c/30a45c0bffdd62350261e2f2689fdba426a33578"}], "title": "vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().", "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": "9c58c729d32e7cea5772cc44929c6cd61e5a31cd", "status": "affected", "version": "5602c48cf87562c2f95b831d690631935e834295", "versionType": "git"}, {"lessThan": "f79c80f173fda9545b220c1f094b65fc06c252d0", "status": "affected", "version": "5602c48cf87562c2f95b831d690631935e834295", "versionType": "git"}, {"lessThan": "08f40c0d23c67c3aa4224c3311e134999c721fb4", "status": "affected", "version": "5602c48cf87562c2f95b831d690631935e834295", "versionType": "git"}, {"lessThan": "4a8cde6f7281ea2c4c290f9ad9923b3631defceb", "status": "affected", "version": "5602c48cf87562c2f95b831d690631935e834295", "versionType": "git"}, {"lessThan": "ef44dac2a37f86eeae6b88ed10a6d60b35387dfd", "status": "affected", "version": "5602c48cf87562c2f95b831d690631935e834295", "versionType": "git"}, {"lessThan": "30a45c0bffdd62350261e2f2689fdba426a33578", "status": "affected", "version": "5602c48cf87562c2f95b831d690631935e834295", "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": "4.7"}, {"lessThan": "4.7", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.178", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "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\nvxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().\n\nudp_tunnel_sock_release() could set sk->sk_user_data to NULL\nwhile vxlan_gro_prepare_receive() is running.\n\nLet's check if rcu_dereference_sk_user_data() is NULL after\nskb_gro_remcsum_init()."}], "id": "CVE-2026-74406", "lastModified": "2026-08-17T06:19:35.850", "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": "2026-08-15T06:22:42.633", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/08f40c0d23c67c3aa4224c3311e134999c721fb4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/30a45c0bffdd62350261e2f2689fdba426a33578"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4a8cde6f7281ea2c4c290f9ad9923b3631defceb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9c58c729d32e7cea5772cc44929c6cd61e5a31cd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ef44dac2a37f86eeae6b88ed10a6d60b35387dfd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f79c80f173fda9545b220c1f094b65fc06c252d0"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive()", "id": "2516806", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516806"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["A flaw was found in the Linux kernel's Virtual Extensible LAN (VXLAN) component. A race condition can occur where the `udp_tunnel_sock_release()` function sets a socket's user data to NULL while the `vxlan_gro_prepare_receive()` function is still actively using it. This could lead to a null pointer dereference, potentially causing a system crash or denial of service."], "name": "CVE-2026-74406", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "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": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "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-2026-74406\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74406\nhttps://lore.kernel.org/linux-cve-announce/2026081510-CVE-2026-74406-5b31@gregkh/T"], "threat_severity": "Moderate"}