# CVE-2026-64263: linux: In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix moving cancelled entry to ent_in... CVE-2026-64263 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-2026-64263 - 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: fuse-uring: fix moving cancelled entry to ent_in_userspace list fuse_uring_cancel() moves entries that are available (these have no reqs attached) to the ent_in_userspace list. ent_list_request_expired() checks the first entry on ent_in_userspace and dereferences ent->fuse_req unconditionally, which will crash on a cancelled entry that was moved to this list. Fix this by freeing the entry and dropping queue_refs directly in fuse_uring_cancel(). This is safe because cancel is the cancel handler itself - after io_uring_cmd_done(), no more cancels will be dispatched for this command, and teardown serializes with cancel via queue->lock. Since cancel now decrements queue_refs, fuse_uring_abort() must no longer gate fuse_uring_abort_end_requests() on queue_refs > 0, as cancelled entries may have already dropped queue_refs while requests are still queued. Remove the gate so abort always flushes requests and stops queues. ## 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-2026-64263](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64263.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 2026-11-08T00:53:09Z 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.