{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-89635 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-89635 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-2026-89635 and fix it if it is affected.\n\nWhat it is: CVE-2026-89635 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-2026-89635 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-2026-89635/ (Markdown: https://insights.sbomify.com/CVE-2026-89635/index.md)","id":"CVE-2026-89635","markdown":"https://insights.sbomify.com/CVE-2026-89635/index.md","name":"CVE-2026-89635","record":{"aliases":["GHSA-rg7m-2q29-w52v","UBUNTU-CVE-2026-89635"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel SMB server","requires_auth":"none","summary":"An authenticated attacker can trigger a use-after-free in the Linux kernel's ksmbd module by reconnecting durable handles, potentially leading to code execution or system crash.","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\nksmbd: only rebind the reopened file's own oplock on durable reconnect\n\nksmbd_reopen_durable_fd() walks the inode's m_op_list and rebinds every\ndetached oplock to the reconnecting session:\n\n\tlist_for_each_entry_rcu(op, \u0026ci-\u003em_op_list, op_entry,\n\t\t\t\tlockdep_is_held(\u0026ci-\u003em_lock)) {\n\t\tif (op-\u003econn)\n\t\t\tcontinue;\n\t\top-\u003econn = ksmbd_conn_get(fp-\u003econn);\n\t\top-\u003esess = work-\u003esess;\n\t}\n\nThe only key is op-\u003econn == NULL, which every detached durable handle on\nthat inode matches, not just the one owned by fp.  When two sessions hold\ndurable handles on the same file and both disconnect, reconnecting one of\nthem adopts the other session's oplock: op-\u003esess is overwritten with the\nreconnecting session without taking a reference on it, while op-\u003econn\npins the connection.\n\nThe sibling teardown path, session_fd_check(), keys on the identity of\nthe connection being torn down (op-\u003econn == conn) rather than on shared\nstate, and so does not have this problem.\n\nOnce the adopting session is destroyed, ksmbd_session_destroy() frees it\nwhile the foreign oplock still points at it.  The reader in\nksmbd_close_fd_app_instance_id() validates only opinfo-\u003econn, which is\nstill live thanks to the reference taken above, and then dereferences the\nstale session:\n\n\tif (!opinfo-\u003econn) {\n\t\tup_read(\u0026fp-\u003ef_ci-\u003em_lock);\n\t\tgoto out;\n\t}\n\n\tft = \u0026opinfo-\u003esess-\u003efile_table;\n\twrite_lock(\u0026ft-\u003elock);\n\n  BUG: KASAN: slab-use-after-free in _raw_write_lock+0x74/0xd0\n  Write of size 4 at addr ffff88810a970528 by task kworker/0:0/9\n  Workqueue: ksmbd-io handle_ksmbd_work\n  Call Trace:\n   _raw_write_lock+0x74/0xd0\n   ksmbd_close_fd_app_instance_id+0x183/0x410\n   smb2_open+0x1346/0x4430\n   handle_ksmbd_work+0x2bb/0x7b0\n\nReached from an authenticated session against a share with the default\ndurable-handle and oplock configuration: two sessions open the same file\nwith a durable-v2 handle and an RH lease under distinct AppInstanceIds,\nboth log off, one reconnects with DH2C, and a later durable-v2 create\ncarrying the other AppInstanceId walks into the freed session.\n\nConstrain the loop to the oplock owned by the file being reopened.","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":"ksmbd: only rebind the reopened file's own oplock on durable reconnect","id":"CVE-2026-89635","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"smb: client: clear ce-\u003etgthint in free_tgts()","id":"CVE-2026-89636"},"packages":[],"prev":{"headline":"smb: client: fix ALIGN() overflow in symlink_data() error context loop","id":"CVE-2026-89634"},"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":"An authenticated attacker can trigger a use-after-free in the Linux kernel's ksmbd module by reconnecting durable handles, potentially leading to code execution or system crash.","url":"https://insights.sbomify.com/CVE-2026-89635/"}