{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-89711 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-89711 is a high-severity 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-2026-89711 and fix it if it is affected.\n\nWhat it is: CVE-2026-89711 is a high-severity 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-2026-89711 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-2026-89711/ (Markdown: https://insights.sbomify.com/CVE-2026-89711/index.md)","id":"CVE-2026-89711","markdown":"https://insights.sbomify.com/CVE-2026-89711/index.md","name":"CVE-2026-89711","record":{"aliases":["AZL-100889","BELL-CVE-2026-89711","DEBIAN-CVE-2026-89711","GHSA-f2q5-7q65-xqx7","UBUNTU-CVE-2026-89711"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"Linux kernel NFSD","requires_auth":"none","summary":"A flawed warning check in the Linux kernel NFSD module can lead to a null pointer dereference during NFS reexports, causing a denial of service.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":8.2,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: remove flawed WARN_ON_ONCE from nfsd_mode_check\n\nThe header for commit e75b23f9e323 (\"nfsd: check d_can_lookup in\nfh_verify of directories\") details the assumption that justified\nadding the WARN_ON_ONCE to nfsd_mode_check(), that assumption is\ninvalid (in the case of NFS reexport).\n\nWhen NFSD exports an NFS filesystem it is very possible for\nnfsd_mode_check() to encounter a @dentry that doesn't have\ni_op-\u003elookup (see nfs_fhget()'s NFS_ATTR_FATTR_MOUNTPOINT and\nNFS_ATTR_FATTR_V4_REFERRAL handling, and d_flags_for_inode()).\n\nSo remove nfsd_mode_check()'s WARN_ON_ONCE(). The nfserr_notdir\nreturn on that branch must stay. It guards the subsequent\nlookup_one_unlocked() -\u003e __lookup_slow() path, which calls\ninode-\u003ei_op-\u003elookup() with no NULL check, so returning nfserr_notdir\nis what keeps a client LOOKUP into such a @dentry from dereferencing\na NULL method pointer.","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: remove flawed WARN_ON_ONCE from nfsd_mode_check","id":"CVE-2026-89711","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock","id":"CVE-2026-89712"},"packages":[],"prev":{"headline":"NFSv4.1: fix layout segment leak on the pnfs_layout_process() forget path","id":"CVE-2026-89710"},"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":"partial"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A flawed warning check in the Linux kernel NFSD module can lead to a null pointer dereference during NFS reexports, causing a denial of service.","url":"https://insights.sbomify.com/CVE-2026-89711/"}