{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43366", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.005Z", "datePublished": "2026-05-08T14:21:19.191Z", "dateUpdated": "2026-08-05T12:27:30.302Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:27:30.302Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/kbuf: check if target buffer list is still legacy on recycle\n\nThere's a gap between when the buffer was grabbed and when it\npotentially gets recycled, where if the list is empty, someone could've\nupgraded it to a ring provided type. This can happen if the request\nis forced via io-wq. The legacy recycling is missing checking if the\nbuffer_list still exists, and if it's of the correct type. Add those\nchecks." } ], "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 code is reachable through local `io_uring_setup`, `io_uring_enter`, and `io_uring_register` operations using provided buffer selection and buffer-ring registration. It is not directly reachable from network packets or physical/adjacent interfaces.\nAC:L - The attacker controls the io_uring ring, the legacy provided buffer group, the in-flight async/io-wq request, and the conversion/removal of the same buffer group. The required timing can be driven by attacker-controlled concurrent local operations, so the race/lifecycle window is low complexity.\nPR:L - Exploitation requires a local unprivileged user able to create and use an io_uring instance; the relevant setup/register/submit paths do not require real root or init-namespace capabilities when io_uring is enabled. This is basic local user privilege, not administrator privilege.\nUI:N - No victim action is required after the attacker runs local code. The attacker performs all setup, submission, and buffer group conversion operations directly.\nS:U - The bug corrupts kernel memory from within the kernel/io_uring security authority and can lead to local kernel compromise or crash. It does not inherently cross a VM, IOMMU, or separate authorization boundary.\nC:H - The legacy recycle path can type-confuse a ring-provided buffer list and write kernel pointers into attacker-observable ring memory, and subsequent use can treat attacker-influenced objects as buffer-ring state. This is kernel memory corruption with a defensible path to high confidentiality impact.\nI:H - Recycling a legacy `struct io_buffer` into a ring buffer list corrupts list/ring state and can turn later ring-buffer operations into controlled kernel memory misuse. As a type confusion/memory corruption bug, high integrity impact is appropriate.\nA:H - If the target buffer list has been removed the old code can dereference a NULL buffer-list pointer, and if it has been upgraded it corrupts kernel state. Either case can produce an oops/panic or otherwise destabilize the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/kbuf.c" ], "versions": [ { "version": "c7fb19428d67dd0a2a78a4f237af01d39c78dc5a", "lessThan": "a7b33671e418fca507feebd1d56e7f4952a4b25c", "status": "affected", "versionType": "git" }, { "version": "c7fb19428d67dd0a2a78a4f237af01d39c78dc5a", "lessThan": "439a6728ec4641ffad1ca796622c19bc525e570f", "status": "affected", "versionType": "git" }, { "version": "c7fb19428d67dd0a2a78a4f237af01d39c78dc5a", "lessThan": "f3fb54e7a8b4aadcc2836ee463eec8c88709b8aa", "status": "affected", "versionType": "git" }, { "version": "c7fb19428d67dd0a2a78a4f237af01d39c78dc5a", "lessThan": "50ad880db3013c6fee0ef13781762a39e2e7ef83", "status": "affected", "versionType": "git" }, { "version": "c7fb19428d67dd0a2a78a4f237af01d39c78dc5a", "lessThan": "97b57f69fee1b61b41acbf37e7720cac9d389fa4", "status": "affected", "versionType": "git" }, { "version": "c7fb19428d67dd0a2a78a4f237af01d39c78dc5a", "lessThan": "c2c185be5c85d37215397c8e8781abf0a69bec1f", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/kbuf.c" ], "versions": [ { "version": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.19", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.9", "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": "5.19", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.18.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.19.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a7b33671e418fca507feebd1d56e7f4952a4b25c" }, { "url": "https://git.kernel.org/stable/c/439a6728ec4641ffad1ca796622c19bc525e570f" }, { "url": "https://git.kernel.org/stable/c/f3fb54e7a8b4aadcc2836ee463eec8c88709b8aa" }, { "url": "https://git.kernel.org/stable/c/50ad880db3013c6fee0ef13781762a39e2e7ef83" }, { "url": "https://git.kernel.org/stable/c/97b57f69fee1b61b41acbf37e7720cac9d389fa4" }, { "url": "https://git.kernel.org/stable/c/c2c185be5c85d37215397c8e8781abf0a69bec1f" } ], "title": "io_uring/kbuf: check if target buffer list is still legacy on recycle", "x_generator": { "engine": "bippy-1.2.0" } } } }