{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98542 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98542 is a denial of service vulnerability in Linux, published on 18 Oct 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-2026-98542 and fix it if it is affected.\n\nWhat it is: CVE-2026-98542 is a denial of service vulnerability in Linux, published on 18 Oct 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-2026-98542 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-2026-98542/ (Markdown: https://insights.sbomify.com/CVE-2026-98542/index.md)","id":"CVE-2026-98542","markdown":"https://insights.sbomify.com/CVE-2026-98542/index.md","name":"CVE-2026-98542","record":{"aliases":["BELL-CVE-2026-98542","DEBIAN-CVE-2026-98542","GHSA-37q5-j4w5-c38r","UBUNTU-CVE-2026-98542"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A logic error in the Linux kernel cpuset controller allows local users to trigger a warning and inconsistent CPU partition state, potentially causing denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"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\ncgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict\n\nWhen a remote partition is created underneath an existing local partition\nvia a non-partition (PRS_MEMBER) intermediate cgroup, update_prstate() sees\nparent-\u003epartition_root_state == PRS_MEMBER and calls\nremote_partition_enable().\n\nCommit 86888c7bd117 (\"cgroup/cpuset: Add warnings to catch inconsistency\nin exclusive CPUs\") replaced the cpumask_intersects(tmp-\u003enew_cpus,\nsubpartitions_cpus) error check in remote_partition_enable() with\nWARN_ON_ONCE(). As a result, remote_partition_enable() emits a warning\nand proceeds to enable the remote partition on CPUs that are already\nowned by the ancestor local partition in subpartitions_cpus.\n\nThis can be reproduced on Linux 7.3.0-rc3 with:\n\n  mkdir -p /tmp/cg1\n  mount -t cgroup2 none /tmp/cg1\n  echo \"+cpuset\" \u003e /tmp/cg1/cgroup.subtree_control\n\n  mkdir /tmp/cg1/A\n  echo 1 \u003e /tmp/cg1/A/cpuset.cpus\n  echo 1 \u003e /tmp/cg1/A/cpuset.cpus.exclusive\n  echo root \u003e /tmp/cg1/A/cpuset.cpus.partition\n  echo \"+cpuset\" \u003e /tmp/cg1/A/cgroup.subtree_control\n\n  mkdir /tmp/cg1/A/B\n  echo 1 \u003e /tmp/cg1/A/B/cpuset.cpus\n  echo 1 \u003e /tmp/cg1/A/B/cpuset.cpus.exclusive\n  echo \"+cpuset\" \u003e /tmp/cg1/A/B/cgroup.subtree_control\n\n  mkdir /tmp/cg1/A/B/D\n  echo 1 \u003e /tmp/cg1/A/B/D/cpuset.cpus\n  echo 1 \u003e /tmp/cg1/A/B/D/cpuset.cpus.exclusive\n  echo root \u003e /tmp/cg1/A/B/D/cpuset.cpus.partition\n\nwhich triggers:\n\n  WARNING: kernel/cgroup/cpuset.c:1594 at remote_partition_enable+0x1c1/0x300\n\nand leaves both /tmp/cg1/A and /tmp/cg1/A/B/D as active root partitions\nclaiming exclusive CPU 1.\n\nFix this by returning PERR_NOCPUS when tmp-\u003enew_cpus intersects\nsubpartitions_cpus in remote_partition_enable(), matching the error code\nused by remote_cpus_update() for the same subpartitions_cpus conflict, and\nadd a regression test case to\ntools/testing/selftests/cgroup/test_cpuset_prs.sh.\n\nTested in QEMU on Linux 7.3.0-rc3 using the reproducer above and\ntools/testing/selftests/cgroup/test_cpuset_prs.sh.","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":"cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict","id":"CVE-2026-98542","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"bpf: fs/xattr: don't assume the inode is locked in path_unlink/path_rmdir","id":"CVE-2026-98543"},"packages":[],"prev":{"headline":"fou: reject omitted FOU_ATTR_IPPROTO on FOU_ENCAP_DIRECT","id":"CVE-2026-98541"},"products":["Linux"],"published":"2026-10-18","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 logic error in the Linux kernel cpuset controller allows local users to trigger a warning and inconsistent CPU partition state, potentially causing denial of service.","url":"https://insights.sbomify.com/CVE-2026-98542/"}