{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98040 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98040 is a memory corruption 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-2026-98040 and fix it if it is affected.\n\nWhat it is: CVE-2026-98040 is a memory corruption 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-2026-98040 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-2026-98040/ (Markdown: https://insights.sbomify.com/CVE-2026-98040/index.md)","id":"CVE-2026-98040","markdown":"https://insights.sbomify.com/CVE-2026-98040/index.md","name":"CVE-2026-98040","record":{"aliases":["DEBIAN-CVE-2026-98040","GHSA-xg34-pxxf-5frp","UBUNTU-CVE-2026-98040"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A flaw in the Linux kernel BPF verifier allows local attackers to bypass NULL checks and dereference null pointers, potentially leading to privilege escalation or code execution.","user_interaction":"not_required","vuln_class":"memory_corruption"},"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: Mark the zero register precise for a register-form NULL check\n\ncheck_cond_jmp_op() accepts \"if rA \u003cop\u003e rB\" as a NULL check for a\nnullable pointer rA when rB is a scalar known to be zero,\nlifts PTR_MAYBE_NULL from rA in the corresponding branch and does not\nmark rB precise. Consider the following program:\n\n  r0 = bpf_get_prandom_u32();\n  r6 = 1;                  /* the r6 == 0 path is explored first */\n  if (r0 == 0) goto 1f;\n  r6 = 0;\n1:\n  r0 = bpf_map_lookup_elem(map, \u00260);  /* absent, NULL at runtime */\n  if (r0 == r6) goto 2f;   /* taken as a NULL check for r0       */\n  *(u8 *)(r0 + 0);         /* verifier: map value; runtime: zero */\n2:\n  return 0;\n\nThe r6 == 0 path is explored first and the dereference is accepted.\nThe r6 == 1 path is pruned at the checkpoint recorded for (1),\nso the comparison is never verified with a non-zero r6. At runtime a\nfailed lookup returns NULL, NULL != 1 takes the non-NULL edge and the\nprogram dereferences a pointer that is zero.","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: Mark the zero register precise for a register-form NULL check","id":"CVE-2026-98040","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"bpf: Don't predict JMP32 pointer vs zero comparisons","id":"CVE-2026-98041"},"packages":[],"prev":{"headline":"bpf: Require MEM_PERCPU for percpu kptr stores","id":"CVE-2026-98039"},"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":"2026-10-19","vendors":["Linux"]},"summary":"A flaw in the Linux kernel BPF verifier allows local attackers to bypass NULL checks and dereference null pointers, potentially leading to privilege escalation or code execution.","url":"https://insights.sbomify.com/CVE-2026-98040/"}