{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98038 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98038 is a vulnerability in Linux, published on 25 Sep 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-2026-98038 and fix it if it is affected.\n\nWhat it is: CVE-2026-98038 is a vulnerability in Linux, published on 25 Sep 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-2026-98038 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-2026-98038/ (Markdown: https://insights.sbomify.com/CVE-2026-98038/index.md)","id":"CVE-2026-98038","markdown":"https://insights.sbomify.com/CVE-2026-98038/index.md","name":"CVE-2026-98038","record":{"aliases":["BELL-CVE-2026-98038","DEBIAN-CVE-2026-98038","GHSA-cwcr-7vrq-384j","UBUNTU-CVE-2026-98038"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel BPF","requires_auth":"low_privilege","summary":"A logic error in the Linux kernel BPF verifier allows null pointer dereferences when handling borrowed RCU pointers, potentially causing a system crash.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Keep refcount_acquire nullable for borrowed RCU kptrs\n\nbpf_refcount_acquire() is fallible for a borrowed reference because the\nobject may have reached a zero refcount. The verifier therefore keeps\nKF_RET_NULL on the return value unless the argument is an owning reference.\n\nAn RCU-protected load of a local kptr is marked MEM_ALLOC, but it only\nreceives NON_OWN_REF when the pointee contains a graph node. A refcounted\nobject without a graph node consequently looks like an owning reference\neven though the loaded register has no acquired reference state. If the\nprogram drops the last real reference while remaining in the RCU critical\nsection, refcount_inc_not_zero() returns NULL while the verifier treats the\nresult as non-NULL.\n\nOnly classify the argument as owning when it is backed by a verifier-tracked\nreference. This retains the non-NULL return for pointers from bpf_obj_new(),\nbpf_kptr_xchg(), or an earlier successful acquisition, while requiring a\nNULL check for borrowed RCU kptrs.\n\n[ kkd: Rewrote commit log ]","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":"bpf: Keep refcount_acquire nullable for borrowed RCU kptrs","id":"CVE-2026-98038","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"bpf: Require MEM_PERCPU for percpu kptr stores","id":"CVE-2026-98039"},"packages":[],"prev":{"headline":"bpf: Reject untrusted allocated-object pointers","id":"CVE-2026-98037"},"products":["Linux"],"published":"2026-09-25","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-21","vendors":["Linux"]},"summary":"A logic error in the Linux kernel BPF verifier allows null pointer dereferences when handling borrowed RCU pointers, potentially causing a system crash.","url":"https://insights.sbomify.com/CVE-2026-98038/"}