{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-68138 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-68138 is a high-severity vulnerability in Linux, published on 10 Aug 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-2026-68138 and fix it if it is affected.\n\nWhat it is: CVE-2026-68138 is a high-severity vulnerability in Linux, published on 10 Aug 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-2026-68138 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-2026-68138/ (Markdown: https://insights.sbomify.com/CVE-2026-68138/index.md)","id":"CVE-2026-68138","markdown":"https://insights.sbomify.com/CVE-2026-68138/index.md","name":"CVE-2026-68138","record":{"aliases":["AZL-95012","BELL-CVE-2026-68138","DEBIAN-CVE-2026-68138","GHSA-5w39-288f-6m96","UBUNTU-CVE-2026-68138"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel's network scheduler allows local attackers to trigger a use-after-free, potentially leading to privilege escalation or code execution.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"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-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: serialize qdisc_rtab_list against concurrent get/put\n\nqdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly\nlinked list qdisc_rtab_list and a plain non-atomic 'int refcnt' with no\nlock. This was only safe because every caller historically held the RTNL\nmutex, which serialized all rate-table lookups, inserts and frees.\n\nThat invariant no longer holds. cls_flower sets\nTCF_PROTO_OPS_DOIT_UNLOCKED, so tc_new_tfilter() keeps rtnl_held == false\nfor it and sets TCA_ACT_FLAGS_NO_RTNL. That flag propagates through\ntcf_exts_validate_ex() -\u003e tcf_action_init() -\u003e tcf_action_init_1() -\u003e\ntcf_police_init(), which calls qdisc_get_rtab()/qdisc_put_rtab() with the\nRTNL mutex NOT held. Two RTM_NEWTFILTER requests on different CPUs, each\nadding a flower filter with a police action carrying the same rate, then\nrace on qdisc_rtab_list and on the non-atomic refcnt, leading to a\nuse-after-free / double-free of the kmalloc-2k struct qdisc_rate_table.\nqdisc_rtab_list is a single global (not per-netns), so the corrupted\nobject is shared system-wide.\n\n  BUG: KASAN: slab-use-after-free in qdisc_put_rtab+0x12f/0x160\n   qdisc_put_rtab+0x12f/0x160\n   tcf_police_init+0xda9/0x1590\n   tcf_action_init_1+0x460/0x6b0\n   tcf_action_init+0x439/0xa40\n   tcf_exts_validate_ex+0x42d/0x550\n   fl_change+0xddd/0x7da0\n   tc_new_tfilter+0xaa7/0x2420\n   rtnetlink_rcv_msg+0x95e/0xe90\n  which belongs to the cache kmalloc-2k of size 2048\n\nProtect qdisc_rtab_list and the refcount with a dedicated spinlock. The\n(sleeping, GFP_KERNEL) allocation in qdisc_get_rtab() is performed before\ntaking the lock; if a concurrent inserter added an identical table in the\nmeantime the freshly allocated one is freed under the lock, so no\nduplicate is leaked. qdisc_put_rtab() now decrements the refcount and\nunlinks under the same lock.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-08-11","github_poc":3,"max_poc_stars":33,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-08-11T22:22:22Z","kind":"github_poc","ref":"https://github.com/aramosf/CVE-2026-68138","stars":33,"title":"CVE-2026-68138 Linux qdisc rate-table race local privilege escalation PoC"},{"date":"2026-08-17T07:33:31Z","kind":"github_poc","ref":"https://github.com/suominen/CVE-2026-68138","stars":0,"title":"Tracking CVE-2026-68138, the Linux kernel net/sched qdisc rate-table use-after-free"},{"date":"2026-08-17T08:04:51Z","kind":"github_poc","ref":"https://github.com/jangkrikkbozz/CVE-2026-68138","stars":0,"title":"CVE-2026-68138 Linux Local Privilege Escalation Exploit"}],"tier":"poc_unverified"},"has_fix":true,"headline":"net/sched: serialize qdisc_rtab_list against concurrent get/put","id":"CVE-2026-68138","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"net/mlx5e: Use sender devcom for MPV master-up","id":"CVE-2026-68139"},"packages":[],"prev":{"headline":"net/x25: fix use-after-free in x25_kill_by_neigh()","id":"CVE-2026-68137"},"products":["Linux"],"published":"2026-08-10","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A race condition in the Linux kernel's network scheduler allows local attackers to trigger a use-after-free, potentially leading to privilege escalation or code execution.","url":"https://insights.sbomify.com/CVE-2026-68138/"}