{"id":"CVE-2026-52912","state":"PUBLISHED","title":"netfilter: nf_queue: hold bridge skb->dev while queued","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_queue: hold bridge skb->dev while queued\n\nbr_pass_frame_up() rewrites skb->dev from the ingress port to the bridge\nmaster before queueing bridge LOCAL_IN packets. NFQUEUE only holds\nreferences on state.in/out and bridge physdevs, so a queued bridge\npacket can retain a freed bridge master in skb->dev until reinjection.\n\nWhen the verdict is reinjected later, br_netif_receive_skb() re-enters\nthe receive path with skb->dev still pointing at the freed bridge master,\ntriggering a use-after-free.\n\nStore skb->dev in the queue entry, hold a reference on it for the queue\nlifetime, and use the saved device when dropping queued packets during\nNETDEV_DOWN handling.","publishedAt":"2026-06-24T07:14:10.583Z","updatedAt":"2026-10-19T19:36:59.798Z","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":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"950d809f154dca04e5fbe5d3c8b9c5e44769cd57","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"a698ac8ab2561cf575d2d9f34095032651dd952e","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"19924bdd8a45ebc72a7b84c57fd63057d1dc75ac","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"1e5e20031c5eee8d2e490a90ff4d6a2feecfc3be","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"3823c27099cfe2482299065814adbaa771be9644","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"15d464265120ab9818bd673af301deee09bedab2","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"3fb0f5c0f64162a8c3f25616a4f1e340b921737f","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"e196115ec330a18de415bdb9f5071aa9f08e53ce","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/netfilter/nf_queue.h","net/netfilter/nf_queue.c","net/netfilter/nfnetlink_queue.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.7","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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_queue.h","net/netfilter/nf_queue.c","net/netfilter/nfnetlink_queue.c"]}],"references":["https://git.kernel.org/stable/c/950d809f154dca04e5fbe5d3c8b9c5e44769cd57","https://git.kernel.org/stable/c/a698ac8ab2561cf575d2d9f34095032651dd952e","https://git.kernel.org/stable/c/19924bdd8a45ebc72a7b84c57fd63057d1dc75ac","https://git.kernel.org/stable/c/1e5e20031c5eee8d2e490a90ff4d6a2feecfc3be","https://git.kernel.org/stable/c/3823c27099cfe2482299065814adbaa771be9644","https://git.kernel.org/stable/c/15d464265120ab9818bd673af301deee09bedab2","https://git.kernel.org/stable/c/3fb0f5c0f64162a8c3f25616a4f1e340b921737f","https://git.kernel.org/stable/c/e196115ec330a18de415bdb9f5071aa9f08e53ce","https://cert-portal.siemens.com/productcert/html/ssa-019113.html","https://cert-portal.siemens.com/productcert/html/ssa-457936.html"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/52xxx/CVE-2026-52912.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52912","state":"PUBLISHED","datePublished":"2026-06-24T07:14:10.583Z","dateUpdated":"2026-10-19T19:36:59.798Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.366Z"},"containers":{"cna":{"title":"netfilter: nf_queue: hold bridge skb->dev while queued","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_queue: hold bridge skb->dev while queued\n\nbr_pass_frame_up() rewrites skb->dev from the ingress port to the bridge\nmaster before queueing bridge LOCAL_IN packets. NFQUEUE only holds\nreferences on state.in/out and bridge physdevs, so a queued bridge\npacket can retain a freed bridge master in skb->dev until reinjection.\n\nWhen the verdict is reinjected later, br_netif_receive_skb() re-enters\nthe receive path with skb->dev still pointing at the freed bridge master,\ntriggering a use-after-free.\n\nStore skb->dev in the queue entry, hold a reference on it for the queue\nlifetime, and use the saved device when dropping queued packets during\nNETDEV_DOWN handling."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"950d809f154dca04e5fbe5d3c8b9c5e44769cd57","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"a698ac8ab2561cf575d2d9f34095032651dd952e","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"19924bdd8a45ebc72a7b84c57fd63057d1dc75ac","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"1e5e20031c5eee8d2e490a90ff4d6a2feecfc3be","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"3823c27099cfe2482299065814adbaa771be9644","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"15d464265120ab9818bd673af301deee09bedab2","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"3fb0f5c0f64162a8c3f25616a4f1e340b921737f","versionType":"git"},{"version":"ac28634456867b23b95faccba7997a62ec430603","status":"affected","lessThan":"e196115ec330a18de415bdb9f5071aa9f08e53ce","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/netfilter/nf_queue.h","net/netfilter/nf_queue.c","net/netfilter/nfnetlink_queue.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.7","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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_queue.h","net/netfilter/nf_queue.c","net/netfilter/nfnetlink_queue.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/950d809f154dca04e5fbe5d3c8b9c5e44769cd57"},{"url":"https://git.kernel.org/stable/c/a698ac8ab2561cf575d2d9f34095032651dd952e"},{"url":"https://git.kernel.org/stable/c/19924bdd8a45ebc72a7b84c57fd63057d1dc75ac"},{"url":"https://git.kernel.org/stable/c/1e5e20031c5eee8d2e490a90ff4d6a2feecfc3be"},{"url":"https://git.kernel.org/stable/c/3823c27099cfe2482299065814adbaa771be9644"},{"url":"https://git.kernel.org/stable/c/15d464265120ab9818bd673af301deee09bedab2"},{"url":"https://git.kernel.org/stable/c/3fb0f5c0f64162a8c3f25616a4f1e340b921737f"},{"url":"https://git.kernel.org/stable/c/e196115ec330a18de415bdb9f5071aa9f08e53ce"}],"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 - Exploitation requires local control of netfilter/NFQUEUE, bridge device lifecycle, and verdict reinjection through netlink/rtnetlink paths. Remote packets alone cannot force the needed bridge teardown and userspace verdict sequence.\nAC:L - A local attacker can deterministically create a namespace, bridge/veth setup, NFQUEUE rule, queued packet, bridge teardown, and reinjection. There is no race dependent on conditions outside attacker control.\nPR:L - The setup requires CAP_NET_ADMIN, but netfilter and bridge configuration are reachable with CAP_NET_ADMIN inside a user-created network namespace on systems allowing unprivileged user namespaces. This is Low, not High.\nUI:N - No victim action is required once the local attacker runs the exploit sequence. The attacker controls packet injection, queueing, device teardown, and verdict delivery.\nS:U - The impact is kernel memory corruption within the same host security authority. This is a standard local kernel privilege escalation/DoS scenario, not a VM or hardware boundary escape.\nC:H - The bug is a use-after-free of the bridge master net_device retained in skb->dev across NFQUEUE. Kernel UAFs can be leveraged for kernel memory disclosure, so confidentiality impact is High.\nI:H - The stale net_device pointer is dereferenced after free in the receive path and can plausibly be combined with heap reclaim/spraying for memory corruption or control-flow impact. As a kernel UAF, integrity impact is High.\nA:H - At minimum, reinjection can dereference freed net_device memory in netif_receive_skb and crash/oops the kernel. Repeated local triggering makes availability impact High."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:31:35.846Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:21:46.948Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-52912","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:22:30.377062Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:36:59.798Z"}}]}}}