{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43403", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.007Z", "datePublished": "2026-05-08T14:21:44.204Z", "dateUpdated": "2026-05-11T22:23:54.491Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T22:23:54.491Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnsfs: tighten permission checks for ns iteration ioctls\n\nEven privileged services should not necessarily be able to see other\nprivileged service's namespaces so they can't leak information to each\nother. Use may_see_all_namespaces() helper that centralizes this policy\nuntil the nstree adapts."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nsfs.c", "include/linux/ns_common.h", "kernel/nscommon.c"], "versions": [{"version": "a1d220d9dafa8d76ba60a784a1016c3134e6a1e8", "lessThan": "3376b345df155ca36d8611857b41ff7d5183fc38", "status": "affected", "versionType": "git"}, {"version": "a1d220d9dafa8d76ba60a784a1016c3134e6a1e8", "lessThan": "2f3dea284c761c890d676f77d5e55c0c496b4ef4", "status": "affected", "versionType": "git"}, {"version": "a1d220d9dafa8d76ba60a784a1016c3134e6a1e8", "lessThan": "0ad650e60150eda789deca5e78a6a09d26bf8fc9", "status": "affected", "versionType": "git"}, {"version": "a1d220d9dafa8d76ba60a784a1016c3134e6a1e8", "lessThan": "e6b899f08066e744f89df16ceb782e06868bd148", "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/nsfs.c", "include/linux/ns_common.h", "kernel/nscommon.c"], "versions": [{"version": "6.12", "status": "affected"}, {"version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.20", "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": "6.12", "versionEndExcluding": "6.12.78"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18.20"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.19.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3376b345df155ca36d8611857b41ff7d5183fc38"}, {"url": "https://git.kernel.org/stable/c/2f3dea284c761c890d676f77d5e55c0c496b4ef4"}, {"url": "https://git.kernel.org/stable/c/0ad650e60150eda789deca5e78a6a09d26bf8fc9"}, {"url": "https://git.kernel.org/stable/c/e6b899f08066e744f89df16ceb782e06868bd148"}], "title": "nsfs: tighten permission checks for ns iteration ioctls", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnsfs: tighten permission checks for ns iteration ioctls\n\nEven privileged services should not necessarily be able to see other\nprivileged service's namespaces so they can't leak information to each\nother. Use may_see_all_namespaces() helper that centralizes this policy\nuntil the nstree adapts."}], "id": "CVE-2026-43403", "lastModified": "2026-05-11T08:16:13.030", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-05-08T15:16:51.783", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0ad650e60150eda789deca5e78a6a09d26bf8fc9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2f3dea284c761c890d676f77d5e55c0c496b4ef4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3376b345df155ca36d8611857b41ff7d5183fc38"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e6b899f08066e744f89df16ceb782e06868bd148"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: nsfs: tighten permission checks for ns iteration ioctls", "id": "2468250", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2468250"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-280", "details": ["A flaw was found in the Linux kernel's `nsfs` component. This vulnerability allows privileged services to bypass permission checks related to namespace iteration input/output controls (ioctls). As a result, one privileged service could potentially view information from other privileged services, leading to unauthorized information disclosure."], "name": "CVE-2026-43403", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-05-08T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-43403\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-43403\nhttps://lore.kernel.org/linux-cve-announce/2026050840-CVE-2026-43403-3869@gregkh/T"], "threat_severity": "Moderate"}