CVE-2026-64588

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64588", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.798Z", "datePublished": "2026-08-06T07:13:46.688Z", "dateUpdated": "2026-08-17T04:58:09.400Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:58:09.400Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix data races on ring->ready\n\nOn weakly-ordered architectures, the store to fiq->ops can be\nreordered past the store to ring->ready, allowing a CPU that sees\nring->ready == true via fuse_uring_ready() to dispatch requests\nthrough a stale fiq->ops pointer. Upgrade the store to\nsmp_store_release() and the load in fuse_uring_ready() to\nsmp_load_acquire() so that the preceding WRITE_ONCE(fiq->ops, ...)\nis visible to any CPU that observes ring->ready == true.\n\nAdditionally, fuse_uring_do_register() publishes ring->ready with\nWRITE_ONCE() but the fast-path check reads it with a plain load.\nThis is a marked-vs-unmarked access that KCSAN will flag. Wrap it in\nREAD_ONCE() to mark it without adding unnecessary ordering.\n\nAlso wrap the fc->ring load in fuse_uring_ready() in READ_ONCE() to\nprevent the compiler from reloading it between the NULL check and the\ndereference."}], "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 bug is reached locally by mounting FUSE with io-uring and submitting IORING_OP_URING_CMD registration while other local threads generate FUSE requests; no network protocol path invokes fuse_uring_ready() or fuse_uring_do_register().\nAC:L - The attacker controls both sides of the race by registering ring entries on /dev/fuse while concurrently issuing filesystem operations on the same mount, so the publish window on weakly ordered CPUs can be driven and retried without relying on victim state.\nPR:L - FUSE is FS_USERNS_MOUNT, so an ordinary user can create a user-namespace mount, open /dev/fuse, and enable FUSE_OVER_IO_URING without init-namespace root privileges.\nUI:N - The attacker can run both the FUSE daemon that registers io-uring queues and the client threads that generate requests on that mount, so no separate victim action is required.\nS:U - Impact is confined to the host kernel authority as a local FUSE/io-uring memory-safety failure, not a VM, IOMMU, or guest-to-host boundary escape.\nC:H - Missing acquire on ring->ready lets CPUs observe readiness while fiq->ops and related ring publication are stale, and the unfixed fc->ring reload in fuse_uring_ready() is a check-then-use UAF window against ring teardown, enabling disclosure of reclaimed kernel memory.\nI:H - Dispatching through inconsistent ops/ring state and the concurrent ring reload UAF allow writes and list/queue operations on stale or reallocated fuse_ring objects, which is exploitable for heap corruption and control-flow hijacking.\nA:H - The same races can NULL-dereference or use a freed fuse_ring in fuse_uring_task_to_queue()/fuse_uring_ready(), hang requests on the wrong queue path, and trigger WARN/oops or panic under panic_on_warn."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fuse/dev_uring.c", "fs/fuse/dev_uring_i.h"], "versions": [{"version": "c2c9af9a0b13261c36909036057a116f2edb5e1a", "lessThan": "b156bb9966972122b148acab8bdf415cdb8176a3", "status": "affected", "versionType": "git"}, {"version": "c2c9af9a0b13261c36909036057a116f2edb5e1a", "lessThan": "d01a09b442cb786cd44ccc7c84d57e2856d6737c", "status": "affected", "versionType": "git"}, {"version": "c2c9af9a0b13261c36909036057a116f2edb5e1a", "lessThan": "46725a0056c884cf58a6897f222892807327d82d", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/fuse/dev_uring.c", "fs/fuse/dev_uring_i.h"], "versions": [{"version": "6.14", "status": "affected"}, {"version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "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": "6.14", "versionEndExcluding": "6.18.39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b156bb9966972122b148acab8bdf415cdb8176a3"}, {"url": "https://git.kernel.org/stable/c/d01a09b442cb786cd44ccc7c84d57e2856d6737c"}, {"url": "https://git.kernel.org/stable/c/46725a0056c884cf58a6897f222892807327d82d"}], "title": "fuse-uring: fix data races on ring->ready", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/fuse/dev_uring.c", "fs/fuse/dev_uring_i.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "b156bb9966972122b148acab8bdf415cdb8176a3", "status": "affected", "version": "c2c9af9a0b13261c36909036057a116f2edb5e1a", "versionType": "git"}, {"lessThan": "d01a09b442cb786cd44ccc7c84d57e2856d6737c", "status": "affected", "version": "c2c9af9a0b13261c36909036057a116f2edb5e1a", "versionType": "git"}, {"lessThan": "46725a0056c884cf58a6897f222892807327d82d", "status": "affected", "version": "c2c9af9a0b13261c36909036057a116f2edb5e1a", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/fuse/dev_uring.c", "fs/fuse/dev_uring_i.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.14"}, {"lessThan": "6.14", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.39", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix data races on ring->ready\n\nOn weakly-ordered architectures, the store to fiq->ops can be\nreordered past the store to ring->ready, allowing a CPU that sees\nring->ready == true via fuse_uring_ready() to dispatch requests\nthrough a stale fiq->ops pointer. Upgrade the store to\nsmp_store_release() and the load in fuse_uring_ready() to\nsmp_load_acquire() so that the preceding WRITE_ONCE(fiq->ops, ...)\nis visible to any CPU that observes ring->ready == true.\n\nAdditionally, fuse_uring_do_register() publishes ring->ready with\nWRITE_ONCE() but the fast-path check reads it with a plain load.\nThis is a marked-vs-unmarked access that KCSAN will flag. Wrap it in\nREAD_ONCE() to mark it without adding unnecessary ordering.\n\nAlso wrap the fc->ring load in fuse_uring_ready() in READ_ONCE() to\nprevent the compiler from reloading it between the NULL check and the\ndereference."}], "id": "CVE-2026-64588", "lastModified": "2026-08-17T05:18:05.207", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-06T08:16:34.123", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/46725a0056c884cf58a6897f222892807327d82d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b156bb9966972122b148acab8bdf415cdb8176a3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d01a09b442cb786cd44ccc7c84d57e2856d6737c"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c2c9af9a0b13261c36909036057a116f2edb5e1a,b156bb9966972122b148acab8bdf415cdb8176a3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c2c9af9a0b13261c36909036057a116f2edb5e1a,d01a09b442cb786cd44ccc7c84d57e2856d6737c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c2c9af9a0b13261c36909036057a116f2edb5e1a,46725a0056c884cf58a6897f222892807327d82d)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "calver", "value": "6.14"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.14)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.39,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.4,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-06T09:00:11.342792+00:00", "updated": "2026-08-08T20:00:04.505936+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-362"]}