{"id":"CVE-2026-74296","state":"PUBLISHED","title":"RDMA/mlx5: Release the HW‑provided UAR index rather than the SW one","description":"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.","publishedAt":"2026-08-15T05:58:00.758Z","updatedAt":"2026-10-16T18:55:31.271Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"80f1f49f53a42733e60c90e0ec545e647969214d","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"aabfc845838ef453f1d22d7665596f9cc48be7dd","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"6f83de384ca582fa87b4c2b0d03bd1ed3bf9a2ee","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"d3ff718c0c7153e2641e6a09507bace14fc5c402","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"ef369446f62903ea079e8a7954b5bf8bb8300fe3","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"449ae7927152e46acbe5f19f97eafdae6d3a96b1","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/hw/mlx5/main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.16","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/hw/mlx5/main.c"]}],"references":["https://git.kernel.org/stable/c/80f1f49f53a42733e60c90e0ec545e647969214d","https://git.kernel.org/stable/c/aabfc845838ef453f1d22d7665596f9cc48be7dd","https://git.kernel.org/stable/c/6f83de384ca582fa87b4c2b0d03bd1ed3bf9a2ee","https://git.kernel.org/stable/c/d3ff718c0c7153e2641e6a09507bace14fc5c402","https://git.kernel.org/stable/c/ef369446f62903ea079e8a7954b5bf8bb8300fe3","https://git.kernel.org/stable/c/449ae7927152e46acbe5f19f97eafdae6d3a96b1"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74296.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74296","state":"PUBLISHED","datePublished":"2026-08-15T05:58:00.758Z","dateUpdated":"2026-10-16T18:55:31.271Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.882Z"},"containers":{"cna":{"title":"RDMA/mlx5: Release the HW‑provided UAR index rather than the SW one","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"80f1f49f53a42733e60c90e0ec545e647969214d","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"aabfc845838ef453f1d22d7665596f9cc48be7dd","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"6f83de384ca582fa87b4c2b0d03bd1ed3bf9a2ee","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"d3ff718c0c7153e2641e6a09507bace14fc5c402","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"ef369446f62903ea079e8a7954b5bf8bb8300fe3","versionType":"git"},{"version":"4ed131d0bb1597ce12fff22d9d7fc9720a6e8cf0","status":"affected","lessThan":"449ae7927152e46acbe5f19f97eafdae6d3a96b1","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/hw/mlx5/main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.16","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/hw/mlx5/main.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:45:34.579Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74296","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:52:36.442847Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:31.271Z"}}]}}}