# CVE-2026-98260: exec: Cleanup POSIX timers right after de_thread() > A use-after-free in the Linux kernel's exec path allows local attackers to execute arbitrary code or escalate privileges via race conditions during thread execution. - **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 6 Oct 2026 - **Updated:** 19 Oct 2026 - **Also known as:** AZL-106044, BELL-CVE-2026-98260, DEBIAN-CVE-2026-98260, GHSA-pr95-77xq-3v99, RHSA-2026:83738, RHSA-2026:83739, RHSA-2026:83775, RHSA-2026:83797, UBUNTU-CVE-2026-98260 ## What is CVE-2026-98260? CVE-2026-98260 is a high-severity use after free vulnerability in Linux, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: exec: Cleanup POSIX timers right after de_thread() A per-thread CPU timer holds a reference to the PID of the thread it is attached to and, while it is armed, its node is queued in that thread's posix_cputimers. The task is looked up by that PID. When a non-leader thread exec()s, de_thread() changes which task owns that PID. pid_task(timer->it.cpu.pid, PIDTYPE_PID) then returns NULL, but the node is still queued on tsk, which is alive. timer_lock_sighand() takes a failed lookup to mean that the node is already dequeued, so it has nothing to undo. begin_new_exec() calls posix_cpu_timers_exit(me) right after exec_task_namespaces() and that removes the leftover node, so the state normally stays invisible. But bprm->point_of_no_return is set before de_thread(), so if unshare_files(), set_mm_exe_file(), exec_mmap() or exec_task_namespaces() fails, the task dies before it gets there. exit_itimers() then frees the k_itimer while its node is still queued, and reaping tsk later erases that freed node from the rbtree. In short: the non-leader thread B the parent timer_create(CLOCK_THREAD_CPUTIME_ID) timer_settime() arm_timer() // the node is queued on B execve() de_thread(B) exchange_tids(B, leader) // B's PID now belongs to the leader release_task(leader) __exit_signal(leader) posix_cpu_timers_exit(leader) // cleans leader's queue, not B's __unhash_process(leader) // that PID has no task anymore exec_mmap() mmap_read_lock_killable(old_mm) kill(B, SIGKILL) // -EINTR get_signal() do_exit() exit_itimers() posix_timer_delete() posix_cpu_timer_del() posix_timer_unhash_and_free() // freed while still queued wait4() release_task(B) posix_cpu_timers_exit(B) cleanup_timerqueue() timerqueue_del() // use-after-free Move the POSIX timer cleanup right after de_thread() before any of the later failure conditions brings the task into do_exit(). [ tglx: Move the cleanup right after de_thread() ] ## Which versions are affected by CVE-2026-98260? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `bpftool-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:7.0.0-284.198.1.el9_2 | | `kernel-64k-debug-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug-devel` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug-devel-matched` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-devel` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-devel-matched` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debug-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debug-devel` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debug-devel-matched` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debuginfo-common-aarch64` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debuginfo-common-ppc64le` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debuginfo-common-s390x` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-debuginfo-common-x86_64` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-devel` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-devel-matched` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-doc` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-tools-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-zfcpdump-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-zfcpdump-devel` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-zfcpdump-devel-matched` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `perf` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `perf-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `python3-perf-debuginfo` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `rtla` | Red Hat:rhel_e4s:9.2::appstream | All versions | 0:5.14.0-284.198.1.el9_2 | | `bpftool` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:7.0.0-284.198.1.el9_2 | | `bpftool-debuginfo` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:7.0.0-284.198.1.el9_2 | | `kernel` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-core` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug-core` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug-debuginfo` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug-modules` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug-modules-core` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debug-modules-extra` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-debuginfo` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-modules` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | | `kernel-64k-modules-core` | Red Hat:rhel_e4s:9.2::baseos | All versions | 0:5.14.0-284.198.1.el9_2 | ## How do I fix CVE-2026-98260? Apply the vendor's patch. ## Is CVE-2026-98260 being exploited? There is no known exploitation of CVE-2026-98260 in the wild and no public exploit code. Public exploit code: - CVE-2026-98260 (Timer) Android/ARM64 port (github_poc): https://github.com/ylh440104/InfinityCore-Android-CVE-2026-98260 - https://github.com/villager1314/CVE-2026-98260-Analysis (github_poc): https://github.com/villager1314/CVE-2026-98260-Analysis - 6.12.69-android16-6-g242e1a07f878 (github_poc): https://github.com/YuKongA/CVE-2026-98260 - Shizuku-driven CVE-2026-98260 root + KernelSU runtime LKM loader for Xiaomi yingtian / lhasa (kernel 6.18.21) (github_poc): https://github.com/zsw125/o3root - GhostKey - CVE-2026-98260 一键提权工具（Shizuku + NDK Native） (github_poc): https://github.com/Again1996-bit/CVE-2026-98260-GhostKey - Target-specific Android CVE-2026-98260 research port for Xiaomi popsicle (github_poc): https://github.com/quyicheng03-boop/CVE-2026-98260-popsicle-android ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-98260 and fix it if it is affected. What it is: CVE-2026-98260 is a high-severity use after free vulnerability in Linux, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-98260 in the wild and no public exploit code. Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. 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. 2. 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. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-98260/ (Markdown: https://insights.sbomify.com/CVE-2026-98260/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98260 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98260 - OSV: https://osv.dev/vulnerability/CVE-2026-98260 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-98260/ Summaries are generated and may contain mistakes; the official description above is the record.