{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23432","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-01-13T15:37:46.016Z","datePublished":"2026-04-03T15:15:18.061Z","dateUpdated":"2026-08-05T12:21:43.430Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:21:43.430Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmshv: Fix use-after-free in mshv_map_user_memory error path\n\nIn the error path of mshv_map_user_memory(), calling vfree() directly on\nthe region leaves the MMU notifier registered. When userspace later unmaps\nthe memory, the notifier fires and accesses the freed region, causing a\nuse-after-free and potential kernel panic.\n\nReplace vfree() with mshv_partition_put() to properly unregister\nthe MMU notifier before freeing the region."}],"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 - The vulnerable path is reached through local `/dev/mshv` and partition-file ioctls, specifically `MSHV_SET_GUEST_MEMORY`, not via network or adjacent protocols.\nAC:L - The attacker controls the memory-region parameters and can subsequently unmap the userspace range to fire the stale MMU notifier. No attacker-uncontrolled race or special victim state is required.\nPR:L - The attacker needs local access to the mshv device or an already-created partition fd, but the vulnerable ioctl itself has no `capable()` check. In a reasonable VMM deployment where that fd/device is granted to a service process, this is Low rather than High.\nUI:N - After obtaining the local mshv interface, the attacker can issue the ioctl and unmap memory without requiring any separate user action.\nS:U - The bug corrupts kernel memory through a kernel driver interface and impacts the same kernel security authority. This is not a guest-to-host escape path from inside a VM.\nC:H - This is a use-after-free of a registered MMU interval notifier embedded in `struct mshv_mem_region`. Reuse of the freed vmalloc object can plausibly expose kernel memory or support read primitives.\nI:H - The stale notifier callback dereferences and writes through fields of freed attacker-reclaimable kernel memory, including notifier sequence and region state. As a kernel UAF, it is plausibly exploitable for memory corruption or control-flow impact.\nA:H - The upstream fix explicitly notes that later userspace unmapping can fire the notifier on freed memory and cause a kernel panic. A local attacker can trigger this repeatedly for host denial of service."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hv/mshv_root_main.c"],"versions":[{"version":"b9a66cd5ccbb9fade15d0e427e19470d8ad35b75","lessThan":"34861bdc0c0196b6c2dd48f7454029407704ff6e","status":"affected","versionType":"git"},{"version":"b9a66cd5ccbb9fade15d0e427e19470d8ad35b75","lessThan":"6922db250422a0dfee34de322f86b7a73d713d33","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/hv/mshv_root_main.c"],"versions":[{"version":"6.19","status":"affected"},{"version":"0","lessThan":"6.19","status":"unaffected","versionType":"semver"},{"version":"6.19.10","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","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":"6.19","versionEndExcluding":"6.19.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.0"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/34861bdc0c0196b6c2dd48f7454029407704ff6e"},{"url":"https://git.kernel.org/stable/c/6922db250422a0dfee34de322f86b7a73d713d33"}],"title":"mshv: Fix use-after-free in mshv_map_user_memory error path","x_generator":{"engine":"bippy-1.2.0"}}}}