{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31678", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.130Z", "datePublished": "2026-04-25T08:46:54.476Z", "dateUpdated": "2026-08-05T12:24:24.631Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:24:24.631Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nopenvswitch: defer tunnel netdev_put to RCU release\n\novs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already\ndetached the device. Dropping the netdev reference in destroy can race\nwith concurrent readers that still observe vport->dev.\n\nDo not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let\nvport_netdev_free() drop the reference from the RCU callback, matching\nthe non-tunnel destroy path and avoiding additional synchronization\nunder RTNL." } ], "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 vulnerable destroy path is reached through local Generic Netlink/rtnetlink control operations that create or delete Open vSwitch tunnel vports. Remote tunnel packets alone do not invoke `ovs_netdev_tunnel_destroy()`.\nAC:L - This is a race/lifetime bug, but the attacker can control both sides by repeatedly deleting tunnel vports while concurrently driving RCU readers such as vport get/dump, packet execute, or datapath traffic. No rare external condition is required.\nPR:L - Creating and deleting OVS datapaths/vports requires `CAP_NET_ADMIN`, but the OVS Generic Netlink families are netns-aware and use `GENL_UNS_ADMIN_PERM`, making this reachable with CAP_NET_ADMIN in an unprivileged user namespace. This is Low privileges rather than High.\nUI:N - No victim user action is needed once the local attacker can issue the relevant netlink operations. The attacker can trigger creation, deletion, and racing reader activity directly.\nS:U - The vulnerability is a kernel memory lifetime error within the same host kernel security authority. It is a standard local kernel privilege-escalation/DoS class issue, not a VM or hardware boundary escape.\nC:H - The early `netdev_put()` can free the `net_device` while RCU readers still dereference `vport->dev`, creating a use-after-free. Per kernel CVSS guidance, UAFs are scored as High confidentiality impact because they can be developed into kernel memory disclosure primitives.\nI:H - The stale `net_device` pointer can be reused after free by kernel readers/writers and may reach function-pointer-bearing netdev paths. Per guidance, a use-after-free is scored as High integrity impact because heap reuse can enable arbitrary write or code execution.\nA:H - The bug can at minimum crash or oops the kernel through NULL/stale `vport->dev` dereferences and has related observed OVS netdev lifetime splats. A kernel UAF also warrants High availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/openvswitch/vport-netdev.c" ], "versions": [ { "version": "a9020fde67a6eb77f8130feff633189f99264db1", "lessThan": "9d56aced21fb9c104e8a3f3be9b21fbafe448ffc", "status": "affected", "versionType": "git" }, { "version": "a9020fde67a6eb77f8130feff633189f99264db1", "lessThan": "42f0d3d81209654c08ffdde5a34b9b92d2645896", "status": "affected", "versionType": "git" }, { "version": "a9020fde67a6eb77f8130feff633189f99264db1", "lessThan": "bbe7bd722bfaea36aab3da6cc60fb4a05c644643", "status": "affected", "versionType": "git" }, { "version": "a9020fde67a6eb77f8130feff633189f99264db1", "lessThan": "98b726ab5e2a4811e27c28e4d041f75bba147eab", "status": "affected", "versionType": "git" }, { "version": "a9020fde67a6eb77f8130feff633189f99264db1", "lessThan": "b8c56a3fc5d879c0928f207a756b0f067f06c6a8", "status": "affected", "versionType": "git" }, { "version": "a9020fde67a6eb77f8130feff633189f99264db1", "lessThan": "6931d21f87bc6d657f145798fad0bf077b82486c", "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/openvswitch/vport-netdev.c" ], "versions": [ { "version": "4.3", "status": "affected" }, { "version": "0", "lessThan": "4.3", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.168", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.131", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.80", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.21", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.11", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "4.3", "versionEndExcluding": "6.1.168" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.3", "versionEndExcluding": "6.6.131" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.3", "versionEndExcluding": "6.12.80" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.3", "versionEndExcluding": "6.18.21" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.3", "versionEndExcluding": "6.19.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.3", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9d56aced21fb9c104e8a3f3be9b21fbafe448ffc" }, { "url": "https://git.kernel.org/stable/c/42f0d3d81209654c08ffdde5a34b9b92d2645896" }, { "url": "https://git.kernel.org/stable/c/bbe7bd722bfaea36aab3da6cc60fb4a05c644643" }, { "url": "https://git.kernel.org/stable/c/98b726ab5e2a4811e27c28e4d041f75bba147eab" }, { "url": "https://git.kernel.org/stable/c/b8c56a3fc5d879c0928f207a756b0f067f06c6a8" }, { "url": "https://git.kernel.org/stable/c/6931d21f87bc6d657f145798fad0bf077b82486c" } ], "title": "openvswitch: defer tunnel netdev_put to RCU release", "x_generator": { "engine": "bippy-1.2.0" } } } }