# CVE-2026-45945: linux: In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix race condition during PASID entr... CVE-2026-45945 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-45945, released May 27, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-45945 - Priority: High - CVSS: 8.8 (high) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 27, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix race condition during PASID entry replacement The Intel VT-d PASID table entry is 512 bits (64 bytes). When replacing an active PASID entry (e.g., during domain replacement), the current implementation calculates a new entry on the stack and copies it to the table using a single structure assignment. struct pasid_entry *pte, new_pte; pte = intel_pasid_get_entry(dev, pasid); pasid_pte_config_first_level(iommu, &new_pte, ...); *pte = new_pte; Because the hardware may fetch the 512-bit PASID entry in multiple 128-bit chunks, updating the entire entry while it is active (Present bit set) risks a "torn" read. In this scenario, the IOMMU hardware could observe an inconsistent state — partially new data and partially old data — leading to unpredictable behavior or spurious faults. Fix this by removing the unsafe "replace" helpers and following the "clear-then-update" flow, which ensures the Present bit is cleared and the required invalidation handshake is completed before the new configuration is applied. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel-livepatch-6.18.39-79.141 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | linux Debian 14 | 6.19.6-1 | [DEBIAN-CVE-2026-45945](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45945.md) | May 27, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.39-79.141.amzn2023 | [ALAS2023-2026-2045](https://patchblox.com/security/data/fix/linux/alas2023-2026-2045.md) | Aug 3, 2026 | --- Data as of 2026-11-08T00:53:09Z UTC. 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