{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-63909 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-63909 is a high-severity memory corruption vulnerability in Linux, published on 19 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-63909 and fix it if it is affected.\n\nWhat it is: CVE-2026-63909 is a high-severity memory corruption vulnerability in Linux, published on 19 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-63909 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-2026-63909/ (Markdown: https://insights.sbomify.com/CVE-2026-63909/index.md)","id":"CVE-2026-63909","markdown":"https://insights.sbomify.com/CVE-2026-63909/index.md","name":"CVE-2026-63909","record":{"aliases":["BELL-CVE-2026-63909","DEBIAN-CVE-2026-63909","GHSA-77x3-ghg7-w5wj","UBUNTU-CVE-2026-63909"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["data_read","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"An out-of-bounds read in the Linux kernel ksmbd module allows attackers to read heap memory or cause a crash during SMB2 operations.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":8.1,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops\n\nCommit d07b26f39246 (\"ksmbd: require minimum ACE size in\nsmb_check_perm_dacl()\") introduced a transposed bounds check:\n\n    if (offsetof(struct smb_ace, sid) + aces_size \u003c CIFS_SID_BASE_SIZE)\n\nSince offsetof(..sid) is 8 and CIFS_SID_BASE_SIZE is 8, this evaluates\nto `aces_size \u003c 0`. Because `aces_size` is always non-negative, this\ncheck becomes dead code and never breaks the loop.\n\nWorse, that commit removed the old 4-byte guard, meaning the loop now\nreads `ace-\u003esize` (offset 2) even when `aces_size` is 0-3 bytes. This\nre-opens a 2-byte heap out-of-bounds (OOB) read past the pntsd allocation\nduring subsequent SMB2_CREATE operations.\n\nFix this by properly transposing the comparison to require at least\n16 bytes (8-byte offset + 8-byte SID base), matching the correct form\nused in smb_inherit_dacl().","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: OOB read regression in smb_check_perm_dacl() ACE-walk loops","id":"CVE-2026-63909","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":7,"next":{"headline":"dma-buf: fix UAF in dma_buf_fd() tracepoint","id":"CVE-2026-63910"},"packages":[],"prev":{"headline":"Input: atmel_mxt_ts - fix boundary check in mxt_prepare_cfg_mem","id":"CVE-2026-63908"},"products":["Linux"],"published":"2026-07-19","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":"2026-08-05","vendors":["Linux"]},"summary":"An out-of-bounds read in the Linux kernel ksmbd module allows attackers to read heap memory or cause a crash during SMB2 operations.","url":"https://insights.sbomify.com/CVE-2026-63909/"}