{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74260", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.877Z", "datePublished": "2026-08-15T05:57:37.579Z", "dateUpdated": "2026-10-15T10:08:50.087Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-15T10:08:50.087Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them\n\nUpdate nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers.\nThis patch also disables BH when transmitting the skb to address a\npossible migration to different CPU leading to imbalanced decrementation\nof the recursion counters.\n\nThis is modeled after Florian Westphal's dev_xmit_recursion*() API\navailable since commit 97cdcf37b57e (\"net: place xmit recursion in\nsoftnet data\") according to its current state in the tree." } ], "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 flaw is reached through nftables netdev fwd/dup evaluation on NF_NETDEV ingress/egress hooks installed via nfnetlink; kernel CNA guidance treats netfilter/nftables configuration and packet-hook paths as Local even when traffic ultimately arrives from the network.\nAC:L - An attacker with CAP_NET_ADMIN can deterministically install netdev egress/ingress fwd or dup rules that loop (same device or mutual forwarding) and drive packets through them; concurrent traffic also lets the attacker influence CPU migration that desynchronizes the per-CPU recursion counter without uncontrollable races.\nPR:L - Installing netdev nftables fwd/dup rules requires CAP_NET_ADMIN via nfnetlink (netlink_net_capable), but that capability is routinely obtainable in an unprivileged-created user+network namespace (unshare -Urn) and is commonly delegated to containers with NET_ADMIN.\nUI:N - Exploitation needs only the attacker's own nftables/netlink setup and packet injection; no victim must mount filesystems, open files, click prompts, or perform any deliberate interactive action beyond ordinary traffic delivery.\nS:U - Impact is unbounded kernel-stack recursion and crash/panic within the same kernel security domain; it does not cross a VM, container, IOMMU, or other distinct security-authority boundary such as guest-to-host escape.\nC:H - Bypassing the nf_dup_skb_recursion limit allows unbounded nf_hook_egress/ingress re-entry that corrupts kernel stack frames before the guard page; such stack corruption can disclose adjacent kernel memory and is not a pure NULL-deref crash with no data exposure.\nI:H - Unbounded recursion overflows the kernel task stack and overwrites saved return addresses/control data on the stack, providing a standard path to arbitrary kernel writes and control-flow hijack rather than a bounded or crash-only integrity effect.\nA:H - When the per-CPU recursion counter is desynchronized by CPU migration without local_bh_disable(), fwd/dup netdev rules can recurse without bound through neigh_xmit/dev_queue_xmit and nf_hook_egress, exhausting the kernel stack and causing oops/panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/netfilter/nf_dup_netdev.h", "net/netfilter/nf_dup_netdev.c", "net/netfilter/nft_fwd_netdev.c" ], "versions": [ { "version": "f37ad91270397a6d053e8623bdb3cf79859691d2", "lessThan": "53fb46cf933dc4361c1a72491e247841d0b0fc85", "status": "affected", "versionType": "git" }, { "version": "f37ad91270397a6d053e8623bdb3cf79859691d2", "lessThan": "edf234f71fb327792196f813048ab8f5bd3bb712", "status": "affected", "versionType": "git" }, { "version": "f37ad91270397a6d053e8623bdb3cf79859691d2", "lessThan": "2354e975932dabb06fad239f07a3b68fd1809737", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/netfilter/nf_dup_netdev.h", "net/netfilter/nf_dup_netdev.c", "net/netfilter/nft_fwd_netdev.c" ], "versions": [ { "version": "6.16", "status": "affected" }, { "version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "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": "6.16", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/53fb46cf933dc4361c1a72491e247841d0b0fc85" }, { "url": "https://git.kernel.org/stable/c/edf234f71fb327792196f813048ab8f5bd3bb712" }, { "url": "https://git.kernel.org/stable/c/2354e975932dabb06fad239f07a3b68fd1809737" } ], "title": "netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them", "x_generator": { "engine": "bippy-1.2.0" } } } }