{ "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" } } } }