{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31718 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-31718 is a critical use after free vulnerability in Linux kernel, published on 1 May 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-2026-31718 and fix it if it is affected.\n\nWhat it is: CVE-2026-31718 is a critical use after free vulnerability in Linux kernel, published on 1 May 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-2026-31718 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-2026-31718/ (Markdown: https://insights.sbomify.com/CVE-2026-31718/index.md)","id":"CVE-2026-31718","markdown":"https://insights.sbomify.com/CVE-2026-31718/index.md","name":"CVE-2026-31718","record":{"aliases":["BELL-CVE-2026-31718","DEBIAN-CVE-2026-31718","GHSA-24c9-h3qq-j27f","UBUNTU-CVE-2026-31718"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A use-after-free in the Linux kernel ksmbd module allows attackers to execute code or escalate privileges via durable file handle cleanup.","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":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":[{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger\n\nWhen a durable file handle survives session disconnect (TCP close without\nSMB2_LOGOFF), session_fd_check() sets fp-\u003econn = NULL to preserve the\nhandle for later reconnection. However, it did not clean up the byte-range\nlocks on fp-\u003elock_list.\n\nLater, when the durable scavenger thread times out and calls\n__ksmbd_close_fd(NULL, fp), the lock cleanup loop did:\n\n    spin_lock(\u0026fp-\u003econn-\u003ellist_lock);\n\nThis caused a slab use-after-free because fp-\u003econn was NULL and the\noriginal connection object had already been freed by\nksmbd_tcp_disconnect().\n\nThe root cause is asymmetric cleanup: lock entries (smb_lock-\u003eclist) were\nleft dangling on the freed conn-\u003elock_list while fp-\u003econn was nulled out.\n\nTo fix this issue properly, we need to handle the lifetime of\nsmb_lock-\u003eclist across three paths:\n - Safely skip clist deletion when list is empty and fp-\u003econn is NULL.\n - Remove the lock from the old connection's lock_list in\n   session_fd_check()\n - Re-add the lock to the new connection's lock_list in\n   ksmbd_reopen_durable_fd().","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: fix use-after-free in __ksmbd_close_fd() via durable scavenger","id":"CVE-2026-31718","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":5,"next":{"headline":"crypto: krb5enc - fix async decrypt skipping hash verification","id":"CVE-2026-31719"},"packages":[],"prev":{"headline":"ksmbd: validate owner of durable handle on reconnect","id":"CVE-2026-31717"},"products":["Linux"],"published":"2026-05-01","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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-05","vendors":["Linux"]},"summary":"A use-after-free in the Linux kernel ksmbd module allows attackers to execute code or escalate privileges via durable file handle cleanup.","url":"https://insights.sbomify.com/CVE-2026-31718/"}