{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-43363 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-43363 is a medium-severity denial of service vulnerability in Linux kernel, published on 8 May 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-2026-43363 and fix it if it is affected.\n\nWhat it is: CVE-2026-43363 is a medium-severity denial of service vulnerability in Linux kernel, published on 8 May 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-2026-43363 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-2026-43363/ (Markdown: https://insights.sbomify.com/CVE-2026-43363/index.md)","id":"CVE-2026-43363","markdown":"https://insights.sbomify.com/CVE-2026-43363/index.md","name":"CVE-2026-43363","record":{"aliases":["BELL-CVE-2026-43363","DEBIAN-CVE-2026-43363","GHSA-j96g-282q-pp54","ROOT-OS-DEBIAN-11-CVE-2026-43363","ROOT-OS-UBUNTU-2204-CVE-2026-43363","ROOT-OS-UBUNTU-2404-CVE-2026-43363","UBUNTU-CVE-2026-43363"],"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 Linux kernel bug causes system hangs during resume from sleep if firmware re-enables x2apic mode unexpectedly.","user_interaction":"not_required","vuln_class":"denial_of_service"},"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":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/apic: Disable x2apic on resume if the kernel expects so\n\nWhen resuming from s2ram, firmware may re-enable x2apic mode, which may have\nbeen disabled by the kernel during boot either because it doesn't support IRQ\nremapping or for other reasons. This causes the kernel to continue using the\nxapic interface, while the hardware is in x2apic mode, which causes hangs.\nThis happens on defconfig + bare metal + s2ram.\n\nFix this in lapic_resume() by disabling x2apic if the kernel expects it to be\ndisabled, i.e. when x2apic_mode = 0.\n\nThe ACPI v6.6 spec, Section 16.3 [1] says firmware restores either the\npre-sleep configuration or initial boot configuration for each CPU, including\nMSR state:\n\n  When executing from the power-on reset vector as a result of waking from an\n  S2 or S3 sleep state, the platform firmware performs only the hardware\n  initialization required to restore the system to either the state the\n  platform was in prior to the initial operating system boot, or to the\n  pre-sleep configuration state. In multiprocessor systems, non-boot\n  processors should be placed in the same state as prior to the initial\n  operating system boot.\n\n  (further ahead)\n\n  If this is an S2 or S3 wake, then the platform runtime firmware restores\n  minimum context of the system before jumping to the waking vector. This\n  includes:\n\n\tCPU configuration. Platform runtime firmware restores the pre-sleep\n\tconfiguration or initial boot configuration of each CPU (MSR, MTRR,\n\tfirmware update, SMBase, and so on). Interrupts must be disabled (for\n\tIA-32 processors, disabled by CLI instruction).\n\n\t(and other things)\n\nSo at least as per the spec, re-enablement of x2apic by the firmware is\nallowed if \"x2apic on\" is a part of the initial boot configuration.\n\n  [1] https://uefi.org/specs/ACPI/6.6/16_Waking_and_Sleeping.html#initialization\n\n  [ bp: Massage. ]","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":"x86/apic: Disable x2apic on resume if the kernel expects so","id":"CVE-2026-43363","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"ublk: fix NULL pointer dereference in ublk_ctrl_set_size()","id":"CVE-2026-43364"},"packages":[],"prev":{"headline":"smb: client: fix in-place encryption corruption in SMB2_write()","id":"CVE-2026-43362"},"products":["Linux"],"published":"2026-05-08","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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A Linux kernel bug causes system hangs during resume from sleep if firmware re-enables x2apic mode unexpectedly.","url":"https://insights.sbomify.com/CVE-2026-43363/"}