{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-89671 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-89671 is a critical missing authorization 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-2026-89671 and fix it if it is affected.\n\nWhat it is: CVE-2026-89671 is a critical missing authorization 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-2026-89671 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-2026-89671/ (Markdown: https://insights.sbomify.com/CVE-2026-89671/index.md)","id":"CVE-2026-89671","markdown":"https://insights.sbomify.com/CVE-2026-89671/index.md","name":"CVE-2026-89671","record":{"aliases":["AZL-100827","BELL-CVE-2026-89671","DEBIAN-CVE-2026-89671","GHSA-j2pv-cprg-p57x","UBUNTU-CVE-2026-89671"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["data_modify"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel NFS","requires_auth":"none","summary":"An attacker can silently delete directory default ACLs via NFSv3 SETACL requests by omitting mask bits, bypassing intended access control modifications.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":9.1,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: gate nfs3 setacl by argp-\u003emask\n\nnfsd3_proc_setacl() calls set_posix_acl() unconditionally for both\nACL_TYPE_ACCESS and ACL_TYPE_DEFAULT, passing argp-\u003eacl_access and\nargp-\u003eacl_default verbatim. The NFSv3 ACL decoder only populates\nthose pointers when the corresponding mask bit is set:\n\n    nfs3svc_decode_setaclargs()\n      if (args-\u003emask \u0026 NFS_ACL)    decode into acl_access\n      if (args-\u003emask \u0026 NFS_DFACL)  decode into acl_default\n      /* otherwise the pointer stays NULL (pc_argzero) */\n\n    nfsd3_proc_setacl()\n      set_posix_acl(.., ACL_TYPE_ACCESS,  argp-\u003eacl_access)\n      set_posix_acl(.., ACL_TYPE_DEFAULT, argp-\u003eacl_default)\n\nset_posix_acl(idmap, dentry, type, NULL) is the VFS \"remove this\nACL type\" operation. A NULL pointer that means \"the client did not\nsend this arm\" is therefore indistinguishable from \"the client\nasked to remove this ACL\". A SETACL with mask=NFS_ACL silently\ndrops the directory's default ACL; mask=0 drops both.\n\nThe sibling nfsd3_proc_getacl() already consults argp-\u003emask before\ntouching each arm; mirror that in setacl.\n\nFix by wrapping each set_posix_acl() call in the matching mask bit\ncheck and initializing error to 0 before inode_lock so that a\nrequest with neither bit set leaves the on-disk ACLs untouched and\nreturns nfs_ok. The out_drop_lock path and the unconditional\nposix_acl_release() at out: are preserved; both NULL-tolerate the\nskipped arms.","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: gate nfs3 setacl by argp-\u003emask","id":"CVE-2026-89671","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"missing_authorization","year":"2026"},"n_packages":0,"n_references":5,"next":{"headline":"nfsd: gate nfs2 setacl by argp-\u003emask","id":"CVE-2026-89672"},"packages":[],"prev":{"headline":"nfsd: hold rcu across localio cmpxchg retry","id":"CVE-2026-89670"},"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":"yes","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"An attacker can silently delete directory default ACLs via NFSv3 SETACL requests by omitting mask bits, bypassing intended access control modifications.","url":"https://insights.sbomify.com/CVE-2026-89671/"}