{"id":"CVE-2026-74260","state":"PUBLISHED","title":"netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them","description":"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.","publishedAt":"2026-08-15T05:57:37.579Z","updatedAt":"2026-10-15T10:08:50.087Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f37ad91270397a6d053e8623bdb3cf79859691d2","status":"affected","lessThan":"53fb46cf933dc4361c1a72491e247841d0b0fc85","versionType":"git"},{"version":"f37ad91270397a6d053e8623bdb3cf79859691d2","status":"affected","lessThan":"edf234f71fb327792196f813048ab8f5bd3bb712","versionType":"git"},{"version":"f37ad91270397a6d053e8623bdb3cf79859691d2","status":"affected","lessThan":"2354e975932dabb06fad239f07a3b68fd1809737","versionType":"git"}],"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"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"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"]}],"references":["https://git.kernel.org/stable/c/53fb46cf933dc4361c1a72491e247841d0b0fc85","https://git.kernel.org/stable/c/edf234f71fb327792196f813048ab8f5bd3bb712","https://git.kernel.org/stable/c/2354e975932dabb06fad239f07a3b68fd1809737"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74260.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74260","state":"PUBLISHED","datePublished":"2026-08-15T05:57:37.579Z","dateUpdated":"2026-10-15T10:08:50.087Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.877Z"},"containers":{"cna":{"title":"netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f37ad91270397a6d053e8623bdb3cf79859691d2","status":"affected","lessThan":"53fb46cf933dc4361c1a72491e247841d0b0fc85","versionType":"git"},{"version":"f37ad91270397a6d053e8623bdb3cf79859691d2","status":"affected","lessThan":"edf234f71fb327792196f813048ab8f5bd3bb712","versionType":"git"},{"version":"f37ad91270397a6d053e8623bdb3cf79859691d2","status":"affected","lessThan":"2354e975932dabb06fad239f07a3b68fd1809737","versionType":"git"}],"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"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"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"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-15T10:08:50.087Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}