{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2025-39977 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-39977 is a high-severity use after free vulnerability in Linux, published on 15 Oct 2025. 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-2025-39977 and fix it if it is affected.\n\nWhat it is: CVE-2025-39977 is a high-severity use after free vulnerability in Linux, published on 15 Oct 2025. 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-2025-39977 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-2025-39977/ (Markdown: https://insights.sbomify.com/CVE-2025-39977/index.md)","id":"CVE-2025-39977","markdown":"https://insights.sbomify.com/CVE-2025-39977/index.md","name":"CVE-2025-39977","record":{"aliases":["AZL-68525","BELL-CVE-2025-39977","DEBIAN-CVE-2025-39977","GHSA-56h7-2ch6-v472","ROOT-OS-DEBIAN-12-CVE-2025-39977","ROOT-OS-DEBIAN-13-CVE-2025-39977","ROOT-OS-UBUNTU-2204-CVE-2025-39977","ROOT-OS-UBUNTU-2404-CVE-2025-39977","UBUNTU-CVE-2025-39977"],"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 race condition in the Linux kernel futex subsystem allows a use-after-free, potentially enabling local attackers to execute arbitrary code or escalate privileges.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Prevent use-after-free during requeue-PI\n\nsyzbot managed to trigger the following race:\n\n   T1                               T2\n\n futex_wait_requeue_pi()\n   futex_do_wait()\n     schedule()\n                               futex_requeue()\n                                 futex_proxy_trylock_atomic()\n                                   futex_requeue_pi_prepare()\n                                   requeue_pi_wake_futex()\n                                     futex_requeue_pi_complete()\n                                      /* preempt */\n\n         * timeout/ signal wakes T1 *\n\n   futex_requeue_pi_wakeup_sync() // Q_REQUEUE_PI_LOCKED\n   futex_hash_put()\n  // back to userland, on stack futex_q is garbage\n\n                                      /* back */\n                                     wake_up_state(q-\u003etask, TASK_NORMAL);\n\nIn this scenario futex_wait_requeue_pi() is able to leave without using\nfutex_q::lock_ptr for synchronization.\n\nThis can be prevented by reading futex_q::task before updating the\nfutex_q::requeue_state. A reference on the task_struct is not needed\nbecause requeue_pi_wake_futex() is invoked with a spinlock_t held which\nimplies a RCU read section.\n\nEven if T1 terminates immediately after, the task_struct will remain valid\nduring T2's wake_up_state().  A READ_ONCE on futex_q::task before\nfutex_requeue_pi_complete() is enough because it ensures that the variable\nis read before the state is updated.\n\nRead futex_q::task before updating the requeue state, use it for the\nfollowing wakeup.","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":"futex: Prevent use-after-free during requeue-PI","id":"CVE-2025-39977","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"use_after_free","year":"2025"},"n_packages":0,"n_references":5,"next":{"headline":"octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()","id":"CVE-2025-39978"},"packages":[],"prev":{"headline":"futex: Use correct exit on failure from futex_hash_allocate_default()","id":"CVE-2025-39976"},"products":["Linux"],"published":"2025-10-15","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":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A race condition in the Linux kernel futex subsystem allows a use-after-free, potentially enabling local attackers to execute arbitrary code or escalate privileges.","url":"https://insights.sbomify.com/CVE-2025-39977/"}