# CVE-2026-64283: linux: In the Linux kernel, the following vulnerability has been resolved: KVM: guest_memfd: Treat memslot binding offset+s... CVE-2026-64283 is fixed in 35 products on 1 platform, first by DEBIAN-CVE-2026-64283, released August 7, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-64283 - Priority: High - CVSS: 7.0 (high) - EPSS: 0.0015 - 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: KVM: guest_memfd: Treat memslot binding offset+size as unsigned values When binding a memslot to a guest_memfd file, treat the offset and size as unsigned values to fix a bug where the sum of the two can result in a false negative when checking for overflow against the size of the file. Passing unsigned values also avoids relying on somewhat obscure checks in other flows for safety, and tracks the offset and size as they are intended to be tracked, as unsigned values. On 64-bit kernels, the number of pages a memslot contains and thus the size (and offset) of its guest_memfd binding are unsigned 64-bit values. Taking the offset+size as an loff_t instead of a uoff_t inadvertently converts the unsigned value to a signed value if the offset and/or size is massive. Locally storing the offset and size as signed values is benign in and of itself (though even that is *extremely* difficult to discern), but operating on their sum is not. For the offset, KVM explicitly checks against a negative value, which might seem like a bug as KVM could incorrectly reject a legitimate binding, but that's not actually the case as KVM_CREATE_GUEST_MEMFD takes a signed value for its size, i.e. a would-be-negative offset is also greater than the maximum possible size of any guest_memfd file. Regarding the size, while KVM lacks an explicit check for a negative value, i.e. seemingly has a flawed overflow check, KVM restricts the number of pages in a single memslot to the largest positive signed 32-bit value: if (id < KVM_USER_MEM_SLOTS && (mem->memory_size >> PAGE_SHIFT) > KVM_MEM_MAX_NR_PAGES) return -EINVAL; and so that maximum "size" will ever be is 0x7fffffff000. The sum of the two is, however, problematic. While the size is restricted by KVM's memslot logic, the offset is not, i.e. the offset is completely unchecked until the "offset + size > i_size_read(inode)" check. If the offset is the (nearly) largest possible _positive_ value, then adding size to the offset can result in a signed, negative 64-bit value. When compared against the size of the file (guaranteed to be positive), the negative sum is always smaller, and KVM incorrectly allows the absurd offset. Opportunistically add missing includes in kvm_mm.h (instead of relying on its parents). ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.38.1.160000.2.22 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.84.1.150700.17.47.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.38.1.160000.2.23 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-livepatch-6.18.44-99.149 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_21 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:4640-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4640-1.md) | Nov 7, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_22 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-64283](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64283.md) | Aug 7, 2026 | | Linux | linux Debian 14 | 7.1.4-1 | [DEBIAN-CVE-2026-64283](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64283.md) | Aug 7, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.44-99.149.amzn2023 | [ALAS2023-2026-2106](https://patchblox.com/security/data/fix/linux/alas2023-2026-2106.md) | Aug 31, 2026 | --- Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.