{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-74439 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-74439 is a critical vulnerability in Linux, published on 15 Aug 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-2026-74439 and fix it if it is affected.\n\nWhat it is: CVE-2026-74439 is a critical vulnerability in Linux, published on 15 Aug 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-2026-74439 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-2026-74439/ (Markdown: https://insights.sbomify.com/CVE-2026-74439/index.md)","id":"CVE-2026-74439","markdown":"https://insights.sbomify.com/CVE-2026-74439/index.md","name":"CVE-2026-74439","record":{"aliases":["BELL-CVE-2026-74439","DEBIAN-CVE-2026-74439","GHSA-3r9j-57rx-vfgp","UBUNTU-CVE-2026-74439"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","other"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel IOMMU","requires_auth":"none","summary":"A race condition in Linux kernel IOMMU teardown allows hardware to access freed memory, potentially causing system crashes or unpredictable behavior.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":9.3,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Clear Present bit before tearing down scalable-mode context entry\n\ndevice_pasid_table_teardown() zeroes the 128-bit scalable-mode context\nentry with context_clear_entry() while the Present bit is still set. This\ncreates a window where the hardware can fetch a torn entry, with some\nfields already zeroed while Present is still set, leading to unpredictable\nbehavior or spurious faults. The context-cache invalidation is issued only\nafter the entry has been zeroed, and intel_pasid_free_table() then frees\nthe PASID directory pages, so the IOMMU can keep walking a stale Present=1\nentry that points at freed memory.\n\nWhile x86 provides strong write ordering, the compiler may reorder the two\n64-bit writes to the entry, and the hardware fetch is not guaranteed to be\natomic with respect to multiple CPU writes.\n\nCommit c1e4f1dccbe9d (\"iommu/vt-d: Clear Present bit before tearing down\ncontext entry\") fixed this exact pattern in domain_context_clear_one() and\nthe copied-context path, but device_pasid_table_teardown() was not\nconverted.\n\nAlign it with the \"Guidance to Software for Invalidations\" in the VT-d\nspec, Section 6.5.3.3, using the same ownership handshake as the sibling\nfix: clear only the Present bit, flush it to the IOMMU, perform the\ncontext-cache invalidation, and only then zero the rest of the entry.","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":"iommu/vt-d: Clear Present bit before tearing down scalable-mode context entry","id":"CVE-2026-74439","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"drm/xe: Wait on external BO kernel fences in exec IOCTL","id":"CVE-2026-74440"},"packages":[],"prev":{"headline":"crypto: sun4i-ss - Remove insecure and unused rng_alg","id":"CVE-2026-74438"},"products":["Linux"],"published":"2026-08-15","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":"2026-10-16","vendors":["Linux"]},"summary":"A race condition in Linux kernel IOMMU teardown allows hardware to access freed memory, potentially causing system crashes or unpredictable behavior.","url":"https://insights.sbomify.com/CVE-2026-74439/"}