{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2025-40026 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-40026 is a high-severity denial of service vulnerability in Linux, published on 28 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-2025-40026 and fix it if it is affected.\n\nWhat it is: CVE-2025-40026 is a high-severity denial of service vulnerability in Linux, published on 28 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-2025-40026 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-2025-40026/ (Markdown: https://insights.sbomify.com/CVE-2025-40026/index.md)","id":"CVE-2025-40026","markdown":"https://insights.sbomify.com/CVE-2025-40026/index.md","name":"CVE-2025-40026","record":{"aliases":["BELL-CVE-2025-40026","DEBIAN-CVE-2025-40026","GHSA-3p46-x25w-pgvh","RHSA-2026:68131","RHSA-2026:78843","RHSA-2026:78844","ROOT-OS-DEBIAN-11-CVE-2025-40026","ROOT-OS-DEBIAN-12-CVE-2025-40026","ROOT-OS-DEBIAN-13-CVE-2025-40026","ROOT-OS-UBUNTU-2204-CVE-2025-40026","ROOT-OS-UBUNTU-2404-CVE-2025-40026","UBUNTU-CVE-2025-40026"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel KVM","requires_auth":"low_privilege","summary":"A flaw in Linux KVM allows a guest to trigger a kernel warning and potential denial of service by modifying I/O permission bitmaps during userspace exits.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":7.9,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Don't (re)check L1 intercepts when completing userspace I/O\n\nWhen completing emulation of instruction that generated a userspace exit\nfor I/O, don't recheck L1 intercepts as KVM has already finished that\nphase of instruction execution, i.e. has already committed to allowing L2\nto perform I/O.  If L1 (or host userspace) modifies the I/O permission\nbitmaps during the exit to userspace,  KVM will treat the access as being\nintercepted despite already having emulated the I/O access.\n\nPivot on EMULTYPE_NO_DECODE to detect that KVM is completing emulation.\nOf the three users of EMULTYPE_NO_DECODE, only complete_emulated_io() (the\nintended \"recipient\") can reach the code in question.  gp_interception()'s\nuse is mutually exclusive with is_guest_mode(), and\ncomplete_emulated_insn_gp() unconditionally pairs EMULTYPE_NO_DECODE with\nEMULTYPE_SKIP.\n\nThe bad behavior was detected by a syzkaller program that toggles port I/O\ninterception during the userspace I/O exit, ultimately resulting in a WARN\non vcpu-\u003earch.pio.count being non-zero due to KVM no completing emulation\nof the I/O instruction.\n\n  WARNING: CPU: 23 PID: 1083 at arch/x86/kvm/x86.c:8039 emulator_pio_in_out+0x154/0x170 [kvm]\n  Modules linked in: kvm_intel kvm irqbypass\n  CPU: 23 UID: 1000 PID: 1083 Comm: repro Not tainted 6.16.0-rc5-c1610d2d66b1-next-vm #74 NONE\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n  RIP: 0010:emulator_pio_in_out+0x154/0x170 [kvm]\n  PKRU: 55555554\n  Call Trace:\n   \u003cTASK\u003e\n   kvm_fast_pio+0xd6/0x1d0 [kvm]\n   vmx_handle_exit+0x149/0x610 [kvm_intel]\n   kvm_arch_vcpu_ioctl_run+0xda8/0x1ac0 [kvm]\n   kvm_vcpu_ioctl+0x244/0x8c0 [kvm]\n   __x64_sys_ioctl+0x8a/0xd0\n   do_syscall_64+0x5d/0xc60\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n   \u003c/TASK\u003e","ecosystems":["Red Hat:rhel_aus:8.6::baseos","Red Hat:rhel_els:7","Red Hat:rhel_eus_long_life:8.6::baseos","Red Hat:rhel_extras_rt_els:7"],"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":"KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O","id":"CVE-2025-40026","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2025"},"n_packages":85,"n_references":9,"next":{"headline":"net/9p: fix double req put in p9_fd_cancelled","id":"CVE-2025-40027"},"packages":[{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"bpftool","purl":"pkg:rpm/redhat/bpftool","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"bpftool-debuginfo","purl":"pkg:rpm/redhat/bpftool-debuginfo","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel","purl":"pkg:rpm/redhat/kernel","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-abi-stablelists","purl":"pkg:rpm/redhat/kernel-abi-stablelists","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-core","purl":"pkg:rpm/redhat/kernel-core","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug","purl":"pkg:rpm/redhat/kernel-debug","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-core","purl":"pkg:rpm/redhat/kernel-debug-core","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-debuginfo","purl":"pkg:rpm/redhat/kernel-debug-debuginfo","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-devel","purl":"pkg:rpm/redhat/kernel-debug-devel","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-modules","purl":"pkg:rpm/redhat/kernel-debug-modules","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-modules-extra","purl":"pkg:rpm/redhat/kernel-debug-modules-extra","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debuginfo","purl":"pkg:rpm/redhat/kernel-debuginfo","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-debuginfo-common-x86_64","purl":"pkg:rpm/redhat/kernel-debuginfo-common-x86_64","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-devel","purl":"pkg:rpm/redhat/kernel-devel","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-doc","purl":"pkg:rpm/redhat/kernel-doc","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-modules","purl":"pkg:rpm/redhat/kernel-modules","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-modules-extra","purl":"pkg:rpm/redhat/kernel-modules-extra","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-tools","purl":"pkg:rpm/redhat/kernel-tools","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-tools-debuginfo","purl":"pkg:rpm/redhat/kernel-tools-debuginfo","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"kernel-tools-libs","purl":"pkg:rpm/redhat/kernel-tools-libs","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"perf","purl":"pkg:rpm/redhat/perf","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"perf-debuginfo","purl":"pkg:rpm/redhat/perf-debuginfo","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"python3-perf","purl":"pkg:rpm/redhat/python3-perf","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_aus:8.6::baseos","fixed":["0:4.18.0-372.214.1.el8_6"],"introduced":["0"],"last_affected":[],"package":"python3-perf-debuginfo","purl":"pkg:rpm/redhat/python3-perf-debuginfo","source":"RHSA-2026:68131"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"bpftool","purl":"pkg:rpm/redhat/bpftool","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"bpftool-debuginfo","purl":"pkg:rpm/redhat/bpftool-debuginfo","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel","purl":"pkg:rpm/redhat/kernel","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-abi-whitelists","purl":"pkg:rpm/redhat/kernel-abi-whitelists","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-bootwrapper","purl":"pkg:rpm/redhat/kernel-bootwrapper","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debug","purl":"pkg:rpm/redhat/kernel-debug","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-debuginfo","purl":"pkg:rpm/redhat/kernel-debug-debuginfo","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debug-devel","purl":"pkg:rpm/redhat/kernel-debug-devel","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debuginfo","purl":"pkg:rpm/redhat/kernel-debuginfo","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debuginfo-common-ppc64","purl":"pkg:rpm/redhat/kernel-debuginfo-common-ppc64","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debuginfo-common-ppc64le","purl":"pkg:rpm/redhat/kernel-debuginfo-common-ppc64le","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debuginfo-common-s390x","purl":"pkg:rpm/redhat/kernel-debuginfo-common-s390x","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-debuginfo-common-x86_64","purl":"pkg:rpm/redhat/kernel-debuginfo-common-x86_64","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-devel","purl":"pkg:rpm/redhat/kernel-devel","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-doc","purl":"pkg:rpm/redhat/kernel-doc","source":"RHSA-2026:78844"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:3.10.0-1160.165.1.el7"],"introduced":["0"],"last_affected":[],"package":"kernel-kdump","purl":"pkg:rpm/redhat/kernel-kdump","source":"RHSA-2026:78844"}],"prev":{"headline":"f2fs: fix to do sanity check on node footer for non inode dnode","id":"CVE-2025-40025"},"products":["Linux"],"published":"2025-10-28","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Red Hat","prefix":"RHSA"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A flaw in Linux KVM allows a guest to trigger a kernel warning and potential denial of service by modifying I/O permission bitmaps during userspace exits.","url":"https://insights.sbomify.com/CVE-2025-40026/"}