{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74296","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.882Z","datePublished":"2026-08-15T05:58:00.758Z","dateUpdated":"2026-08-17T05:45:34.579Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:45:34.579Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/mlx5: Release the HW‑provided UAR index rather than the SW one\n\nFree the UAR index returned by the hardware."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires a local mmap(2) on an opened mlx5 uverbs file descriptor (/dev/infiniband/uverbs*); the bug is in uar_mmap() error cleanup and is not reachable via remote RDMA/network packet handling.\nAC:L - An attacker who can open uverbs and issue MLX5_IB_MMAP_ALLOC_WC can reliably reach the faulty cleanup by forcing rdma_user_mmap_io()/io_remap_pfn_range() to fail (e.g., memory or VMA map pressure), and controls all syscall parameters for the race-free trigger.\nPR:L - Any unprivileged local user with access to the mlx5 RDMA character device (default 0666 uverbs nodes on shared HPC/cloud compute nodes with ConnectX NICs) can alloc a context and mmap; no real-root or CAP_SYS_ADMIN capability is required.\nUI:N - Exploitation is fully attacker-driven through uverbs open, alloc_ucontext, and mmap syscalls; no victim interaction such as mounting filesystems or opening files is needed.\nS:U - Impact is confined to kernel/driver and RDMA device resource integrity on the host; it does not cross a VM-hypervisor or IOMMU security boundary into a different authority.\nC:H - Deallocating the wrong hardware UAR index frees another context's live UAR while the attacker-allocated UAR leaks, creating a cross-context UAR use-after-free that can expose other users' MMIO doorbell/register mappings and device state.\nI:H - UAR pages provide userspace MMIO write access to mlx5 doorbells and control registers; corrupting or reassigning UAR ownership enables arbitrary device register/DMA manipulation and is exploitable for privilege escalation beyond simple data tampering.\nA:H - Freeing an in-use hardware UAR from another context can cause kernel oops/panic, NIC hangs, or repeated crashes when victims continue doorbell/MMIO access through stale mappings."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/hw/mlx5/main.c"],"versions":[{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","lessThan":"80f1f49f53a42733e60c90e0ec545e647969214d","status":"affected","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","lessThan":"aabfc845838ef453f1d22d7665596f9cc48be7dd","status":"affected","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","lessThan":"6f83de384ca582fa87b4c2b0d03bd1ed3bf9a2ee","status":"affected","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","lessThan":"d3ff718c0c7153e2641e6a09507bace14fc5c402","status":"affected","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","lessThan":"ef369446f62903ea079e8a7954b5bf8bb8300fe3","status":"affected","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","lessThan":"449ae7927152e46acbe5f19f97eafdae6d3a96b1","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/hw/mlx5/main.c"],"versions":[{"version":"4.16","status":"affected"},{"version":"0","lessThan":"4.16","status":"unaffected","versionType":"semver"},{"version":"6.1.178","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.145","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.97","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.16","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/80f1f49f53a42733e60c90e0ec545e647969214d"},{"url":"https://git.kernel.org/stable/c/aabfc845838ef453f1d22d7665596f9cc48be7dd"},{"url":"https://git.kernel.org/stable/c/6f83de384ca582fa87b4c2b0d03bd1ed3bf9a2ee"},{"url":"https://git.kernel.org/stable/c/d3ff718c0c7153e2641e6a09507bace14fc5c402"},{"url":"https://git.kernel.org/stable/c/ef369446f62903ea079e8a7954b5bf8bb8300fe3"},{"url":"https://git.kernel.org/stable/c/449ae7927152e46acbe5f19f97eafdae6d3a96b1"}],"title":"RDMA/mlx5: Release the HW‑provided UAR index rather than the SW one","x_generator":{"engine":"bippy-1.2.0"}}}}