{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-64139 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-64139 is a medium-severity denial of service vulnerability in Linux kernel, published on 19 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-2026-64139 and fix it if it is affected.\n\nWhat it is: CVE-2026-64139 is a medium-severity denial of service vulnerability in Linux kernel, published on 19 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-2026-64139 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-2026-64139/ (Markdown: https://insights.sbomify.com/CVE-2026-64139/index.md)","id":"CVE-2026-64139","markdown":"https://insights.sbomify.com/CVE-2026-64139/index.md","name":"CVE-2026-64139","record":{"aliases":["BELL-CVE-2026-64139","DEBIAN-CVE-2026-64139","GHSA-3c28-w5w6-mh56","ROOT-OS-DEBIAN-12-CVE-2026-64139","UBUNTU-CVE-2026-64139"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel ksmbd","requires_auth":"low_privilege","summary":"A memory leak in the Linux kernel ksmbd module allows attackers to exhaust kernel memory via malformed POSIX ACL entries, causing denial of service.","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":[{"id":"CWE-401","name":"Missing Release of Memory after Effective Lifetime"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow\n\nCommit 299f962c0b02 (\"ksmbd: use check_add_overflow() to prevent u16\nDACL size overflow\") added check_add_overflow() guards that break out\nof the ACE-building loops in set_posix_acl_entries_dacl() when the\naccumulated DACL size would wrap past 65535.\n\nHowever, each iteration allocates a struct smb_sid via kmalloc_obj()\nat the top of the loop and relies on the kfree(sid) call at the end\nof the loop body (the 'pass_same_sid' label in the first loop, and\nthe explicit kfree at the tail of the second loop) to release it.\nThe newly introduced 'break' statements bypass those kfree() calls,\nleaking the sid buffer every time an overflow is detected.\n\nA malicious or malformed file with enough POSIX ACL entries to trip\nthe overflow check will leak one or more struct smb_sid allocations\non every request that touches the file's DACL, providing a trivial\nkernel memory exhaustion vector.\n\nFree sid before breaking out of the loops to plug the leak.","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 SID memory leak in set_posix_acl_entries_dacl() on overflow","id":"CVE-2026-64139","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":6,"next":{"headline":"ksmbd: fix null pointer dereference in proc_show_files()","id":"CVE-2026-64140"},"packages":[],"prev":{"headline":"ksmbd: validate SID in parent security descriptor during ACL inheritance","id":"CVE-2026-64138"},"products":["Linux"],"published":"2026-07-19","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":"2026-08-23","vendors":["Linux"]},"summary":"A memory leak in the Linux kernel ksmbd module allows attackers to exhaust kernel memory via malformed POSIX ACL entries, causing denial of service.","url":"https://insights.sbomify.com/CVE-2026-64139/"}