{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-23405", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:46.012Z", "datePublished": "2026-04-01T08:36:35.697Z", "dateUpdated": "2026-04-01T08:36:35.697Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-04-01T08:36:35.697Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix: limit the number of levels of policy namespaces\n\nCurrently the number of policy namespaces is not bounded relying on\nthe user namespace limit. However policy namespaces aren't strictly\ntied to user namespaces and it is possible to create them and nest\nthem arbitrarily deep which can be used to exhaust system resource.\n\nHard cap policy namespaces to the same depth as user namespaces."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["security/apparmor/include/policy_ns.h", "security/apparmor/policy_ns.c"], "versions": [{"version": "c88d4c7b049e87998ac0a9f455aa545cc895ef92", "lessThan": "3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e", "status": "affected", "versionType": "git"}, {"version": "c88d4c7b049e87998ac0a9f455aa545cc895ef92", "lessThan": "853ce31ca72097d23991a06876a2ccb5cb64b603", "status": "affected", "versionType": "git"}, {"version": "c88d4c7b049e87998ac0a9f455aa545cc895ef92", "lessThan": "d42b2b6bb77ca40ee34ab74ad79305840b5f315d", "status": "affected", "versionType": "git"}, {"version": "c88d4c7b049e87998ac0a9f455aa545cc895ef92", "lessThan": "7b6495ead2c611647f6b11441a852324e3eb8616", "status": "affected", "versionType": "git"}, {"version": "c88d4c7b049e87998ac0a9f455aa545cc895ef92", "lessThan": "306039414932c80f8420695a24d4fe10c84ccfb2", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["security/apparmor/include/policy_ns.h", "security/apparmor/policy_ns.c"], "versions": [{"version": "2.6.36", "status": "affected"}, {"version": "0", "lessThan": "2.6.36", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.77", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.18", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.8", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0-rc4", "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": "2.6.36", "versionEndExcluding": "6.6.130"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.12.77"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.18.18"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.19.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "7.0-rc4"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e"}, {"url": "https://git.kernel.org/stable/c/853ce31ca72097d23991a06876a2ccb5cb64b603"}, {"url": "https://git.kernel.org/stable/c/d42b2b6bb77ca40ee34ab74ad79305840b5f315d"}, {"url": "https://git.kernel.org/stable/c/7b6495ead2c611647f6b11441a852324e3eb8616"}, {"url": "https://git.kernel.org/stable/c/306039414932c80f8420695a24d4fe10c84ccfb2"}], "title": "apparmor: fix: limit the number of levels of policy namespaces", "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\napparmor: fix: limit the number of levels of policy namespaces\n\nCurrently the number of policy namespaces is not bounded relying on\nthe user namespace limit. However policy namespaces aren't strictly\ntied to user namespaces and it is possible to create them and nest\nthem arbitrarily deep which can be used to exhaust system resource.\n\nHard cap policy namespaces to the same depth as user namespaces."}], "id": "CVE-2026-23405", "lastModified": "2026-04-01T14:23:37.727", "metrics": {}, "published": "2026-04-01T09:16:16.153", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/306039414932c80f8420695a24d4fe10c84ccfb2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7b6495ead2c611647f6b11441a852324e3eb8616"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/853ce31ca72097d23991a06876a2ccb5cb64b603"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d42b2b6bb77ca40ee34ab74ad79305840b5f315d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: apparmor: fix: limit the number of levels of policy namespaces", "id": "2453795", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2453795"}, "csaw": false, "cwe": "CWE-770", "details": ["A flaw was found in the AppArmor security module within the Linux kernel. A local user could exploit this vulnerability by creating and nesting policy namespaces without limit. This unbounded nesting can lead to the exhaustion of system resources, resulting in a Denial of Service (DoS) for the affected system."], "name": "CVE-2026-23405", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not 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": "2026-04-01T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-23405\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-23405\nhttps://lore.kernel.org/linux-cve-announce/2026040111-CVE-2026-23405-0e7a@gregkh/T"]}