{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-46319 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-46319 is a high-severity use after free vulnerability in Linux kernel, published on 9 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-46319 and fix it if it is affected.\n\nWhat it is: CVE-2026-46319 is a high-severity use after free vulnerability in Linux kernel, published on 9 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-46319 in the wild and no public exploit code.\n\nAffected product: Linux kernel. 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-2026-46319/ (Markdown: https://insights.sbomify.com/CVE-2026-46319/index.md)","id":"CVE-2026-46319","markdown":"https://insights.sbomify.com/CVE-2026-46319/index.md","name":"CVE-2026-46319","record":{"aliases":["AZL-89681","BELL-CVE-2026-46319","DEBIAN-CVE-2026-46319","GHSA-q9hw-vhj5-hw57","ROOT-OS-DEBIAN-11-CVE-2026-46319","ROOT-OS-DEBIAN-12-CVE-2026-46319","ROOT-OS-DEBIAN-13-CVE-2026-46319","ROOT-OS-UBUNTU-2204-CVE-2026-46319","ROOT-OS-UBUNTU-2404-CVE-2026-46319","UBUNTU-CVE-2026-46319"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A use-after-free vulnerability in the Linux kernel's net/sched act_ct module allows local attackers to escalate privileges due to improper RCU lock handling.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-416","name":"Use After Free"},{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ct: Only release RCU read lock after ct_ft\n\nWhen looking up a flow table in act_ct in tcf_ct_flow_table_get(),\nrhashtable_lookup_fast() internally opens and closes an RCU read critical\nsection before returning ct_ft.\nThe tcf_ct_flow_table_cleanup_work() can complete before refcount_inc_not_zero()\nis invoked on the returned ct_ft resulting in a UAF on the already freed ct_ft\nobject. This vulnerability can lead to privilege escalation.\n\nAnalysis from zdi-disclosures@trendmicro.com:\nWhen initializing act_ct, tcf_ct_init() is called, which internally triggers\ntcf_ct_flow_table_get().\n\nstatic int tcf_ct_flow_table_get(struct net *net, struct tcf_ct_params *params)\n\n{\n                struct zones_ht_key key = { .net = net, .zone = params-\u003ezone };\n                struct tcf_ct_flow_table *ct_ft;\n                int err = -ENOMEM;\n\n                mutex_lock(\u0026zones_mutex);\n                ct_ft = rhashtable_lookup_fast(\u0026zones_ht, \u0026key, zones_params); // [1]\n                if (ct_ft \u0026\u0026 refcount_inc_not_zero(\u0026ct_ft-\u003eref)) // [2]\n                                goto out_unlock;\n                ...\n}\n\nstatic __always_inline void *rhashtable_lookup_fast(\n                struct rhashtable *ht, const void *key,\n                const struct rhashtable_params params)\n{\n                void *obj;\n\n                rcu_read_lock();\n                obj = rhashtable_lookup(ht, key, params);\n                rcu_read_unlock();\n\n                return obj;\n}\n\nAt [1], rhashtable_lookup_fast() looks up and returns the corresponding ct_ft\nfrom zones_ht . The lookup is performed within an RCU read critical section\nthrough rcu_read_lock() / rcu_read_unlock(), which prevents the object from\nbeing freed. However, at the point of function return, rcu_read_unlock() has\nalready been called, and there is nothing preventing ct_ft from being freed\nbefore reaching refcount_inc_not_zero(\u0026ct_ft-\u003eref) at [2]. This interval becomes\nthe race window, during which ct_ft can be freed.\n\nFree Process:\n\ntcf_ct_flow_table_put() is executed through the path tcf_ct_cleanup() call_rcu()\ntcf_ct_params_free_rcu() tcf_ct_params_free() tcf_ct_flow_table_put().\n\nstatic void tcf_ct_flow_table_put(struct tcf_ct_flow_table *ct_ft)\n{\n                if (refcount_dec_and_test(\u0026ct_ft-\u003eref)) {\n                                rhashtable_remove_fast(\u0026zones_ht, \u0026ct_ft-\u003enode, zones_params);\n                                INIT_RCU_WORK(\u0026ct_ft-\u003erwork, tcf_ct_flow_table_cleanup_work); // [3]\n                                queue_rcu_work(act_ct_wq, \u0026ct_ft-\u003erwork);\n                }\n}\n\nAt [3], tcf_ct_flow_table_cleanup_work() is scheduled as RCU work\n\nstatic void tcf_ct_flow_table_cleanup_work(struct work_struct *work)\n\n{\n                struct tcf_ct_flow_table *ct_ft;\n                struct flow_block *block;\n\n                ct_ft = container_of(to_rcu_work(work), struct tcf_ct_flow_table,\n                                                                rwork);\n                nf_flow_table_free(\u0026ct_ft-\u003enf_ft);\n                block = \u0026ct_ft-\u003enf_ft.flow_block;\n                down_write(\u0026ct_ft-\u003enf_ft.flow_block_lock);\n                WARN_ON(!list_empty(\u0026block-\u003ecb_list));\n                up_write(\u0026ct_ft-\u003enf_ft.flow_block_lock);\n                kfree(ct_ft); // [4]\n\n                module_put(THIS_MODULE);\n}\n\ntcf_ct_flow_table_cleanup_work() frees ct_ft at [4]. When this function executes\nbetween [1] and [2], UAF occurs.\n\nThis race condition has a very short race window, making it generally\ndifficult to trigger. Therefore, to trigger the vulnerability an msleep(100) was\ninserted after[1]","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"net/sched: act_ct: Only release RCU read lock after ct_ft","id":"CVE-2026-46319","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"tap: free page on error paths in tap_get_user_xdp()","id":"CVE-2026-46320"},"packages":[],"prev":{"headline":"Revert \"mm/hugetlbfs: update hugetlbfs to use mmap_prepare\"","id":"CVE-2026-46318"},"products":["Linux"],"published":"2026-06-09","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel's net/sched act_ct module allows local attackers to escalate privileges due to improper RCU lock handling.","url":"https://insights.sbomify.com/CVE-2026-46319/"}