{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-89713 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-89713 is a critical 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-2026-89713 and fix it if it is affected.\n\nWhat it is: CVE-2026-89713 is a critical 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-2026-89713 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-2026-89713/ (Markdown: https://insights.sbomify.com/CVE-2026-89713/index.md)","id":"CVE-2026-89713","markdown":"https://insights.sbomify.com/CVE-2026-89713/index.md","name":"CVE-2026-89713","record":{"aliases":["AZL-100142","BELL-CVE-2026-89713","DEBIAN-CVE-2026-89713","GHSA-v99p-5h33-35p9","UBUNTU-CVE-2026-89713"],"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":"A race condition in the Linux kernel NFS server allows attackers to bypass append-only file protections and truncate files via concurrent operations.","user_interaction":"not_required","vuln_class":"race_condition"},"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:N/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: check truncate permission under inode lock\n\nnfsd_setattr() checks whether a size update needs NFSD_MAY_TRUNC\nbefore it takes inode_lock(). The comparison uses the file size sampled\nby that unlocked read, but the actual ATTR_SIZE update is applied later\nunder inode_lock() by notify_change().\n\nThis leaves a TOCTOU window for append-only files. If a client sends a\nSETATTR that does not shrink the file at the time of the unlocked\nsample, a concurrent append can extend the file before nfsd_setattr()\ntakes inode_lock(). notify_change() then applies a real truncation\nwithout the NFSD_MAY_TRUNC check that rejects IS_APPEND(inode). The VFS\ntruncate syscall paths perform their own append-only checks before\ncalling notify_change(), so NFSD must make this decision against the\nlocked size it is about to change.\n\nSplit the write-count acquisition from the truncation permission check.\nKeep get_write_access() before the locked setattr work, then recheck\nwhether the requested size is below i_size_read(inode) after inode_lock()\nhas been acquired and before notify_change(ATTR_SIZE). This also avoids\nthe plain unlocked inode-\u003ei_size load.","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: check truncate permission under inode lock","id":"CVE-2026-89713","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":5,"next":{"headline":"NFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails","id":"CVE-2026-89714"},"packages":[],"prev":{"headline":"NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock","id":"CVE-2026-89712"},"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":"2026-10-21","vendors":["Linux"]},"summary":"A race condition in the Linux kernel NFS server allows attackers to bypass append-only file protections and truncate files via concurrent operations.","url":"https://insights.sbomify.com/CVE-2026-89713/"}