{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98432 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98432 is a critical use after free vulnerability in Linux, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-98432 and fix it if it is affected.\n\nWhat it is: CVE-2026-98432 is a critical use after free vulnerability in Linux, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-98432 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-98432/ (Markdown: https://insights.sbomify.com/CVE-2026-98432/index.md)","id":"CVE-2026-98432","markdown":"https://insights.sbomify.com/CVE-2026-98432/index.md","name":"CVE-2026-98432","record":{"aliases":["AZL-108246","BELL-CVE-2026-98432","DEBIAN-CVE-2026-98432","GHSA-qp6h-4hvh-qqqc","UBUNTU-CVE-2026-98432"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A use-after-free vulnerability in the Linux kernel IPv4 stack allows remote attackers to cause a denial of service or potentially execute code via crafted TCP packets.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":9.8,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: free inet_opt and ireq_opt after an RCU grace period\n\ntcp_v4_syn_recv_sock() transfers ownership of ireq-\u003eireq_opt to the\nchild socket (newinet-\u003einet_opt) without copying it.\n\nAnother cpu can concurrently process a retransmitted SYN for the same\nrequest socket, and send a SYNACK from tcp_check_req().\ntcp_v4_send_synack() and inet_csk_route_req() read ireq-\u003eireq_opt\nunder rcu_read_lock() only, and ip_build_and_send_pkt() and\nip_options_build() then read opt-\u003eoptlen twice.\n\nNote that the SYNACK timer itself is not an issue: it holds a\nreference on its request socket, and inet_csk_reqsk_queue_drop()\ncalls timer_delete_sync() before the child can be freed.\n\nSince commit 079096f103fa (\"tcp/dccp: install syn_recv requests\ninto ehash table\"), request sockets are processed without holding\nthe listener lock, so nothing prevents the child socket from being\nfreed while the SYNACK is still being built. TCP child sockets do\nnot have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt\nwith a plain kfree(), leading to a use-after-free in\nip_options_build().\n\nA similar issue exists with request socket migration\n(net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE\nprogram). reqsk_timer_handler() clones the request socket with\ninet_reqsk_clone(), so that the old request socket and its clone\nshare the same ireq_opt, then reqsk_migrate_reset() clears the\npointer in the old one. Another cpu holding a reference on the old\nrequest socket can still be using these options (sending a SYNACK,\nor creating a child in tcp_v4_syn_recv_sock()) when the clone is\nfreed, and tcp_v4_reqsk_destructor() also uses a plain kfree().\n\nReaders already use RCU, and other paths replacing inet_opt\n(do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use\nkfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and\ntcp_v4_reqsk_destructor() as well.\n\nIPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock()\nduplicates the options. tcp_v6_reqsk_destructor() has the same\nmigration issue with ipv6_opt, which is only set by CALIPSO. This\nwill be addressed in a separate patch.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-10-29","github_poc":11,"max_poc_stars":1,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-10-30T00:22:53Z","kind":"github_poc","ref":"https://github.com/H1z3-br0/CVE-2026-98432","stars":1,"title":"Race trigger, heap-reuse oracle, pcap analysis, detection and mitigation tooling for CVE-2026-98432 (Linux IPv4/TCP ireq_opt use-after-free)."},{"date":"2026-10-29T14:17:42Z","kind":"github_poc","ref":"https://github.com/Quaerendir/cve-2026-98432-audit","stars":0,"title":"cve-2026-98432 audit script (ipv4 TCP inet_opt/ireq_opt use-after-free)"},{"date":"2026-10-29T14:58:31Z","kind":"github_poc","ref":"https://github.com/suominen/CVE-2026-98432","stars":0,"title":null},{"date":"2026-10-29T16:58:02Z","kind":"github_poc","ref":"https://github.com/nsrg-fmlorg/kpatch-cve-2026-98432","stars":0,"title":"kpatch livepatch for CVE-2026-98432 (and CVE-2026-99999) on AlmaLinux and Rocky Linux 8, 9 and 10"},{"date":"2026-10-29T17:22:03Z","kind":"github_poc","ref":"https://github.com/typhoon1217/cve-2026-98432-mitigation","stars":0,"title":"Temporary mitigation for CVE-2026-98432 (Linux IPv4 TCP ireq_opt use-after-free): drop IPv4 TCP with IP options, disable MPTCP. Tested scripts + verification. EN/KO."},{"date":"2026-10-29T17:40:25Z","kind":"github_poc","ref":"https://github.com/axisops/CVE-2026-98432","stars":0,"title":"Linux kernel IPv4 SYN IP-options use-after-free CVE-2026-98432 Mitigation work (Ansible Role)"},{"date":"2026-10-29T22:00:04Z","kind":"github_poc","ref":"https://github.com/techtaek77/ubuntu-tcp-guide","stars":0,"title":"우분투 커널 TCP 구멍(CVE-2026-98432) 쉽게 보기 · 벨로키 보안 공부"},{"date":"2026-10-30T00:24:18Z","kind":"github_poc","ref":"https://github.com/mahdi-salmanzade/CVE-2026-98432","stars":0,"title":"CVE-2026-98432 (Linux IPv4 TCP use-after-free): how to check your server, apply a stopgap, and clean up after the fix"}],"tier":"poc_unverified"},"has_fix":true,"headline":"ipv4: free inet_opt and ireq_opt after an RCU grace period","id":"CVE-2026-98432","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"KVM: PPC: Book3S HV: fix secure device page leak on uv_page_in() failure","id":"CVE-2026-98433"},"packages":[],"prev":{"headline":"RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency","id":"CVE-2026-98431"},"products":["Linux"],"published":"2026-10-15","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-24","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel IPv4 stack allows remote attackers to cause a denial of service or potentially execute code via crafted TCP packets.","url":"https://insights.sbomify.com/CVE-2026-98432/"}