{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23159 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23159 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 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-2026-23159 and fix it if it is affected.\n\nWhat it is: CVE-2026-23159 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 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-2026-23159 in the wild and no public exploit code.\n\nAffected product: Linux kernel. 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-2026-23159/ (Markdown: https://insights.sbomify.com/CVE-2026-23159/index.md)","id":"CVE-2026-23159","markdown":"https://insights.sbomify.com/CVE-2026-23159/index.md","name":"CVE-2026-23159","record":{"aliases":["BELL-CVE-2026-23159","DEBIAN-CVE-2026-23159","GHSA-398f-64gc-qxqm","ROOT-OS-UBUNTU-2404-CVE-2026-23159","UBUNTU-CVE-2026-23159"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel perf subsystem can cause a null pointer dereference crash when profiling tasks during exit.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf: sched: Fix perf crash with new is_user_task() helper\n\nIn order to do a user space stacktrace the current task needs to be a user\ntask that has executed in user space. It use to be possible to test if a\ntask is a user task or not by simply checking the task_struct mm field. If\nit was non NULL, it was a user task and if not it was a kernel task.\n\nBut things have changed over time, and some kernel tasks now have their\nown mm field.\n\nAn idea was made to instead test PF_KTHREAD and two functions were used to\nwrap this check in case it became more complex to test if a task was a\nuser task or not[1]. But this was rejected and the C code simply checked\nthe PF_KTHREAD directly.\n\nIt was later found that not all kernel threads set PF_KTHREAD. The io-uring\nhelpers instead set PF_USER_WORKER and this needed to be added as well.\n\nBut checking the flags is still not enough. There's a very small window\nwhen a task exits that it frees its mm field and it is set back to NULL.\nIf perf were to trigger at this moment, the flags test would say its a\nuser space task but when perf would read the mm field it would crash with\nat NULL pointer dereference.\n\nNow there are flags that can be used to test if a task is exiting, but\nthey are set in areas that perf may still want to profile the user space\ntask (to see where it exited). The only real test is to check both the\nflags and the mm field.\n\nInstead of making this modification in every location, create a new\nis_user_task() helper function that does all the tests needed to know if\nit is safe to read the user space memory or not.\n\n[1] https://lore.kernel.org/all/20250425204120.639530125@goodmis.org/","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":"perf: sched: Fix perf crash with new is_user_task() helper","id":"CVE-2026-23159","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"octeon_ep: Fix memory leak in octep_device_setup()","id":"CVE-2026-23160"},"packages":[],"prev":{"headline":"gpio: virtuser: fix UAF in configfs release path","id":"CVE-2026-23158"},"products":["Linux"],"published":"2026-02-14","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-23","vendors":["Linux"]},"summary":"A race condition in the Linux kernel perf subsystem can cause a null pointer dereference crash when profiling tasks during exit.","url":"https://insights.sbomify.com/CVE-2026-23159/"}