{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-89688 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-89688 is a critical use after free vulnerability in Linux, published on 11 Sep 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-2026-89688 and fix it if it is affected.\n\nWhat it is: CVE-2026-89688 is a critical use after free vulnerability in Linux, published on 11 Sep 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-2026-89688 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-2026-89688/ (Markdown: https://insights.sbomify.com/CVE-2026-89688/index.md)","id":"CVE-2026-89688","markdown":"https://insights.sbomify.com/CVE-2026-89688/index.md","name":"CVE-2026-89688","record":{"aliases":["BELL-CVE-2026-89688","DEBIAN-CVE-2026-89688","GHSA-mq7m-fxw5-rr6m","UBUNTU-CVE-2026-89688"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel NFS server","requires_auth":"none","summary":"A refcount underflow in the Linux kernel NFS server allows attackers to trigger a use-after-free, potentially leading to code execution or denial of service.","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\nnfsd: drop the stateid, not the stateowner, on seqid_op replay retry\n\nIn nfs4_preprocess_seqid_op() the stateid is obtained from\nnfsd4_lookup_stateid(), which holds a reference on the nfs4_stid\n(sc_count) but takes no reference on the stateowner. openlockstateid()\nmerely casts that stid and likewise takes no reference.\n\nWhen nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is\nbeing torn down, RP_UNHASHED) it has not taken a stateowner reference on\nthat path. The error handling nevertheless called\nnfs4_put_stateowner(stp-\u003est_stateowner), dropping an so_count reference\nthe function never acquired -- risking a stateowner refcount underflow and\nuse-after-free -- while leaking the sc_count reference held on the stid.\nThe leaked stid reference can also stall a concurrent\nnfsd4_close_open_stateid() waiting for sc_count to drop.\n\nDrop the reference actually held -- the stid -- before retrying. The\nstateowner stays alive through the reference held by the stid. This mirrors\nthe open path in nfsd4_process_open1(), where the put balances a reference\nthat path explicitly holds on the stateowner.","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":"nfsd: drop the stateid, not the stateowner, on seqid_op replay retry","id":"CVE-2026-89688","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"nfsd: don't free session slots that are still in use","id":"CVE-2026-89689"},"packages":[],"prev":{"headline":"nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file","id":"CVE-2026-89687"},"products":["Linux"],"published":"2026-09-11","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A refcount underflow in the Linux kernel NFS server allows attackers to trigger a use-after-free, potentially leading to code execution or denial of service.","url":"https://insights.sbomify.com/CVE-2026-89688/"}