{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-64262 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-64262 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Jul 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-2026-64262 and fix it if it is affected.\n\nWhat it is: CVE-2026-64262 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Jul 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-2026-64262 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-2026-64262/ (Markdown: https://insights.sbomify.com/CVE-2026-64262/index.md)","id":"CVE-2026-64262","markdown":"https://insights.sbomify.com/CVE-2026-64262/index.md","name":"CVE-2026-64262","record":{"aliases":["BELL-CVE-2026-64262","DEBIAN-CVE-2026-64262","GHSA-fxm4-5828-j89m","ROOT-OS-UBUNTU-2204-CVE-2026-64262","UBUNTU-CVE-2026-64262"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A flaw in the Linux kernel's fuse-uring module causes a denial of service by leaking references and stalling background operations when io_uring tasks are cancelled.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: end fuse_req on io-uring cancel task work\n\nWhen io_uring delivers task work with tw.cancel set (PF_EXITING,\nPF_KTHREAD fallback, or percpu_ref_is_dying on the ring context),\nfuse_uring_send_in_task() takes the cancel branch, assigns\n-ECANCELED, and falls through to fuse_uring_send(). That path only\nflips the entry to FRRS_USERSPACE and completes the io_uring cmd;\nit never discharges the ring entry's owning reference to the\nfuse_req that fuse_uring_add_req_to_ring_ent() handed it at\ndispatch time.\n\n    fuse_uring_send_in_task()\n      tw.cancel == true\n        err = -ECANCELED\n      fuse_uring_send(ent, cmd, err, issue_flags)\n        ent-\u003estate = FRRS_USERSPACE\n        list_move(\u0026ent-\u003elist, \u0026queue-\u003eent_in_userspace)\n        ent-\u003ecmd = NULL\n        io_uring_cmd_done(-ECANCELED)\n        /* ent-\u003efuse_req still set, req still hashed */\n\nThe fuse_req stays linked on fpq-\u003eprocessing[hash] and\nfuse_request_end() is never invoked. The originating syscall\nthread blocks in D-state in request_wait_answer() until\nfuse_abort_conn() runs, which can be the entire connection\nlifetime. For FR_BACKGROUND requests fc-\u003enum_background is never\ndecremented either, so repeated cancels inflate the counter until\nmax_background is hit and all later background ops stall. tw.cancel does\nnot imply a connection abort (e.g. a single io_uring worker thread exits\nwhile the fuse connection stays up), so this cannot be left for\nfuse_abort_conn() to clean up.\n\nEnding the req but still routing the entry through fuse_uring_send()\nis not enough: that leaves a req-less entry on ent_in_userspace, and\nent_list_request_expired() dereferences ent-\u003efuse_req unconditionally\non the head of that list, which would then NULL-deref.\n\nFix the cancel branch to release the entry directly. Remove it from the\nqueue, complete the io_uring cmd, end the fuse_req, free the entry, and\ndrop its queue_refs (waking the teardown waiter if it was the last).","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":"fuse-uring: end fuse_req on io-uring cancel task work","id":"CVE-2026-64262","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"fuse-uring: fix moving cancelled entry to ent_in_userspace list","id":"CVE-2026-64263"},"packages":[],"prev":{"headline":"fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues","id":"CVE-2026-64261"},"products":["Linux"],"published":"2026-07-25","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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-17","vendors":["Linux"]},"summary":"A flaw in the Linux kernel's fuse-uring module causes a denial of service by leaking references and stalling background operations when io_uring tasks are cancelled.","url":"https://insights.sbomify.com/CVE-2026-64262/"}