{"answers":{"affected":"It affects 2 products.","exploited":"There is no known exploitation of CVE-2025-39866 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-39866 is a high-severity use after free vulnerability in Debian Debian Linux, published on 19 Sep 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-2025-39866 and fix it if it is affected.\n\nWhat it is: CVE-2025-39866 is a high-severity use after free vulnerability in Debian Debian Linux, published on 19 Sep 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-2025-39866 in the wild and no public exploit code.\n\nAffected product: Debian Debian 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-2025-39866/ (Markdown: https://insights.sbomify.com/CVE-2025-39866/index.md)","id":"CVE-2025-39866","markdown":"https://insights.sbomify.com/CVE-2025-39866/index.md","name":"CVE-2025-39866","record":{"aliases":["AZL-67578","AZL-75119","BELL-CVE-2025-39866","DEBIAN-CVE-2025-39866","GHSA-65ww-5pr7-752v","ROOT-OS-DEBIAN-11-CVE-2025-39866","ROOT-OS-DEBIAN-12-CVE-2025-39866","ROOT-OS-DEBIAN-13-CVE-2025-39866","ROOT-OS-UBUNTU-2204-CVE-2025-39866","ROOT-OS-UBUNTU-2404-CVE-2025-39866","UBUNTU-CVE-2025-39866"],"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 use-after-free in the Linux kernel writeback subsystem allows local attackers to potentially execute code or escalate privileges via race conditions.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"debian_linux","vendor":"debian"},{"product":"linux_kernel","vendor":"linux"}],"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":[{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs: writeback: fix use-after-free in __mark_inode_dirty()\n\nAn use-after-free issue occurred when __mark_inode_dirty() get the\nbdi_writeback that was in the progress of switching.\n\nCPU: 1 PID: 562 Comm: systemd-random- Not tainted 6.6.56-gb4403bd46a8e #1\n......\npstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : __mark_inode_dirty+0x124/0x418\nlr : __mark_inode_dirty+0x118/0x418\nsp : ffffffc08c9dbbc0\n........\nCall trace:\n __mark_inode_dirty+0x124/0x418\n generic_update_time+0x4c/0x60\n file_modified+0xcc/0xd0\n ext4_buffered_write_iter+0x58/0x124\n ext4_file_write_iter+0x54/0x704\n vfs_write+0x1c0/0x308\n ksys_write+0x74/0x10c\n __arm64_sys_write+0x1c/0x28\n invoke_syscall+0x48/0x114\n el0_svc_common.constprop.0+0xc0/0xe0\n do_el0_svc+0x1c/0x28\n el0_svc+0x40/0xe4\n el0t_64_sync_handler+0x120/0x12c\n el0t_64_sync+0x194/0x198\n\nRoot cause is:\n\nsystemd-random-seed                         kworker\n----------------------------------------------------------------------\n___mark_inode_dirty                     inode_switch_wbs_work_fn\n\n  spin_lock(\u0026inode-\u003ei_lock);\n  inode_attach_wb\n  locked_inode_to_wb_and_lock_list\n     get inode-\u003ei_wb\n     spin_unlock(\u0026inode-\u003ei_lock);\n     spin_lock(\u0026wb-\u003elist_lock)\n  spin_lock(\u0026inode-\u003ei_lock)\n  inode_io_list_move_locked\n  spin_unlock(\u0026wb-\u003elist_lock)\n  spin_unlock(\u0026inode-\u003ei_lock)\n                                    spin_lock(\u0026old_wb-\u003elist_lock)\n                                      inode_do_switch_wbs\n                                        spin_lock(\u0026inode-\u003ei_lock)\n                                        inode-\u003ei_wb = new_wb\n                                        spin_unlock(\u0026inode-\u003ei_lock)\n                                    spin_unlock(\u0026old_wb-\u003elist_lock)\n                                    wb_put_many(old_wb, nr_switched)\n                                      cgwb_release\n                                      old wb released\n  wb_wakeup_delayed() accesses wb,\n  then trigger the use-after-free\n  issue\n\nFix this race condition by holding inode spinlock until\nwb_wakeup_delayed() finished.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2025-09-26","github_poc":1,"max_poc_stars":4,"metasploit":0,"nuclei":0,"refs":[{"date":"2025-09-26T15:35:50Z","kind":"github_poc","ref":"https://github.com/byteReaper77/CVE-2025-39866","stars":4,"title":"Proof of concept for CVE-2025-39866 (UAF and race condition)"}],"tier":"poc_unverified"},"has_fix":true,"headline":"fs: writeback: fix use-after-free in __mark_inode_dirty()","id":"CVE-2025-39866","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"debian:debian_linux","products":["debian:debian_linux","linux:linux_kernel"],"type":"use_after_free","year":"2025"},"n_packages":0,"n_references":7,"next":{"headline":"This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.","id":"CVE-2025-39867"},"packages":[],"prev":{"headline":"tee: fix NULL pointer dereference in tee_shm_put","id":"CVE-2025-39865"},"products":["Linux"],"published":"2025-09-19","related":[{"cvss_score":10,"headline":"ProFTPD Improper Access Control","id":"CVE-2015-3306","kev_date_added":"2026-10-08","published":"2015-05-18"},{"cvss_score":9.9,"headline":"RoundCube Webmail Deserialization of Untrusted Data","id":"CVE-2025-49113","kev_date_added":"2026-02-20","published":"2025-06-02"},{"cvss_score":9.8,"headline":"GNU InetUtils Argument Injection","id":"CVE-2026-24061","kev_date_added":"2026-01-26","published":"2026-01-21"},{"cvss_score":9.8,"headline":"Linux Kernel Improper Check for Unusual or Exceptional Conditions","id":"CVE-2025-39682","kev_date_added":"2026-09-18","published":"2025-09-05"},{"cvss_score":9.8,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2024-9680","kev_date_added":"2024-10-15","published":"2024-10-09"},{"cvss_score":9.8,"headline":"RARLAB UnRAR Directory Traversal","id":"CVE-2022-30333","kev_date_added":"2022-08-09","published":"2022-05-09"},{"cvss_score":9.8,"headline":"Roundcube Webmail SQL Injection","id":"CVE-2021-44026","kev_date_added":"2023-06-22","published":"2021-11-19"}],"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)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A use-after-free in the Linux kernel writeback subsystem allows local attackers to potentially execute code or escalate privileges via race conditions.","url":"https://insights.sbomify.com/CVE-2025-39866/"}