# CVE-2026-64302: linux: In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix freeing of PMD-sized vmemmap pages... CVE-2026-64302 is fixed in 20 products on 1 platform, first by ALAS2023-2026-1881, released June 22, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-64302 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0016 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 22, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix freeing of PMD-sized vmemmap pages Commit bf9e4e30f353 ("x86/mm: use pagetable_free()"), switched from freeing non-boot page tables through __free_pages() to pagetable_free(). However, the function is also called to free vmemmap pages. Given that vmemmap pages are not page tables, already the page_ptdesc(page) is wrong. But worse, pagetable_free() calls: __free_pages(page, compound_order(page)); Since vmemmap pages are not compound pages (see vmemmap_alloc_block()) -- except for HVO, which doesn't apply here -- only first page of a PMD-sized vmemmap page is freed, leaking the other ones. Fix it by properly decoupling pagetable and vmemmap freeing. free_pagetable() no longer has to mess with SECTION_INFO, as only the vmemmap is marked like that in register_page_bootmem_memmap(). The indentation in remove_pmd_table() is messed up. Fix that while touching it. Bootmem info handling will soon be fixed up. For now, handle it similar to free_pagetable(), just avoiding the ifdef. [ dhansen: changelog munging. More imperative voice ] ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel-livepatch-6.18.35-68.127 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | linux Debian 14 | 7.1.4-1 | [DEBIAN-CVE-2026-64302](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64302.md) | Aug 7, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 | --- Data as of 2026-11-08T06:59:42Z UTC. 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