# CVE-2026-64291: linux: In the Linux kernel, the following vulnerability has been resolved: iommufd: Set veventq_depth upper bound iommufd_... CVE-2026-64291 is fixed in 20 products on 1 platform, first by ALAS2023-2026-2045, released August 3, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-64291 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0016 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 25, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: iommufd: Set veventq_depth upper bound iommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with an upper bound at U32_MAX. This leaves a vulnerability where userspace can allocate excessively large queues to exhaust kernel memory reserves. Cap the veventq_depth (maximum number of entries) to 1 << 19, matching the maximum number of entries in the SMMUv3 EVTQ (the largest use case today). ## 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 | 7.1.4-1 | [DEBIAN-CVE-2026-64291](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64291.md) | Aug 7, 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 2026-11-08T13:06:02Z UTC. 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