{ "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→udp4_gro_receive→udp_tunnel_gro_rcv→vxlan_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" } } } }