{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72405","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-09T03:40:39.925Z","datePublished":"2026-08-15T05:56:29.466Z","dateUpdated":"2026-08-17T05:43:45.202Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:43:45.202Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_sync\n\nYue Sun reported a use-after-free and debugobjects warning in\nudp_tunnel_nic_device_sync_work() during concurrent device operations.\n\nThe workqueue core clears the internal pending bit before invoking the\nworker. At that point, a concurrent thread can queue the work again.\nWhen the already running worker eventually clears the work_pending flag\nto 0, it mistakenly clears the flag for the newly queued instance.\nudp_tunnel_nic_unregister() then observes work_pending as 0 and frees\nthe structure while the second work item is still active in the queue,\nleading to UAF.\n\nFix this by returning early in udp_tunnel_nic_device_sync() if\nwork_pending is already set, preventing redundant work queueing."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through local netlink/RTNL paths (VXLAN/Geneve tunnel socket create/delete, netdev feature updates, or netdev unregister) that queue udp_tunnel_nic_device_sync; remote UDP/VXLAN packets do not enter this offload management code.\nAC:L - An attacker can reliably win the race by running concurrent tunnel create/delete or netdev operations in multiple threads; both the double-queue and the premature free depend on attacker-controlled timing, not on uncontrollable system state.\nPR:L - Triggering udp_tunnel_notify_add/del_rx_port requires CAP_NET_ADMIN (e.g. ip link add/del vxlan/geneve), which unprivileged users can obtain in a user/network namespace via unshare; no remote or pre-auth network path exists.\nUI:N - Exploitation requires only programmatic tunnel or netdev manipulation via netlink; no victim user action such as opening a file or mounting a filesystem is needed.\nS:U - Impact is kernel heap corruption and potential privilege escalation within the same kernel/host security domain; it does not by itself cross a VM, container, or IOMMU boundary to another authority.\nC:H - The flaw is a use-after-free of struct udp_tunnel_nic; freed offload state can be reallocated and read through the still-queued work handler, enabling arbitrary kernel memory disclosure.\nI:H - UAF on the udp_tunnel_nic work item and its entries allows heap grooming and corrupting kernel objects/driver callbacks, supporting arbitrary write and potential kernel code execution.\nA:H - Use-after-free in a workqueue handler on a shared offload path can cause kernel oops/panic or wedged NIC offload during concurrent tunnel churn, producing total loss of availability."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/udp_tunnel_nic.c"],"versions":[{"version":"cc4e3835eff474aa274d6e1d18f69d9d296d3b76","lessThan":"cee6688e5731c0591643521716d1a1a5c1a98bf8","status":"affected","versionType":"git"},{"version":"cc4e3835eff474aa274d6e1d18f69d9d296d3b76","lessThan":"9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7","status":"affected","versionType":"git"},{"version":"cc4e3835eff474aa274d6e1d18f69d9d296d3b76","lessThan":"54292b167466cdf42176b7b6f01da66c184deb12","status":"affected","versionType":"git"},{"version":"cc4e3835eff474aa274d6e1d18f69d9d296d3b76","lessThan":"ecf69d4b43370c587e48d4d70289dbdb7e039d4d","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/ipv4/udp_tunnel_nic.c"],"versions":[{"version":"5.9","status":"affected"},{"version":"0","lessThan":"5.9","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":"5.9","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/cee6688e5731c0591643521716d1a1a5c1a98bf8"},{"url":"https://git.kernel.org/stable/c/9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7"},{"url":"https://git.kernel.org/stable/c/54292b167466cdf42176b7b6f01da66c184deb12"},{"url":"https://git.kernel.org/stable/c/ecf69d4b43370c587e48d4d70289dbdb7e039d4d"}],"title":"net: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_sync","x_generator":{"engine":"bippy-1.2.0"}}}}