{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89707", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.751Z", "datePublished": "2026-09-11T19:46:23.293Z", "dateUpdated": "2026-09-11T19:46:23.293Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-11T19:46:23.293Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: release path refs on follow_down() error\n\nnfsd_cross_mnt() initializes a local struct path with mntget() and\ndget() before calling follow_down(). On a negative return the error\narm jumps to out without releasing those references:\n\n err = follow_down(&path, follow_flags);\n if (err < 0)\n goto out;\n\nfollow_down() never drops the caller's entry-time refs on any error\nsub-case; for example a pre-cross d_manage() failure leaves path\nuntouched, so the mntget()/dget() taken on entry survive the call.\n\nEvery other early-exit arm in nfsd_cross_mnt() (other-namespace\nreturn, IS_ERR(exp2), and the success tail after the swap) already\ncalls path_put(&path); the err < 0 arm is the lone omission. The\nleak inflates mnt_count and d_count on each failed cross-mount,\nblocking umount and pinning dentries against the shrinker, and is\nreachable by any authenticated NFS client through nfsd_lookup_dentry\nor the NFSv4 READDIR encode path.\n\nFix by calling path_put(&path) before the goto out in the err < 0\narm so the entry-time refs are released on all follow_down() error\nreturns."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfsd/vfs.c"], "versions": [{"version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "lessThan": "194316df81263519156ebe714c4a286bee00e5be", "status": "affected", "versionType": "git"}, {"version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "lessThan": "467d56fd3ff57447a790c6dc3ede2d02a947d224", "status": "affected", "versionType": "git"}, {"version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "lessThan": "2bc4343308d85ee4e0dd3877b384306c96f114c2", "status": "affected", "versionType": "git"}, {"version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "lessThan": "6cba08dc1922140d260cfeb30bbda4ee1bf869d8", "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/nfsd/vfs.c"], "versions": [{"version": "2.6.38", "status": "affected"}, {"version": "0", "lessThan": "2.6.38", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc1", "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": "2.6.38", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "7.3-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/194316df81263519156ebe714c4a286bee00e5be"}, {"url": "https://git.kernel.org/stable/c/467d56fd3ff57447a790c6dc3ede2d02a947d224"}, {"url": "https://git.kernel.org/stable/c/2bc4343308d85ee4e0dd3877b384306c96f114c2"}, {"url": "https://git.kernel.org/stable/c/6cba08dc1922140d260cfeb30bbda4ee1bf869d8"}], "title": "nfsd: release path refs on follow_down() error", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/nfsd/vfs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "194316df81263519156ebe714c4a286bee00e5be", "status": "affected", "version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "versionType": "git"}, {"lessThan": "467d56fd3ff57447a790c6dc3ede2d02a947d224", "status": "affected", "version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "versionType": "git"}, {"lessThan": "2bc4343308d85ee4e0dd3877b384306c96f114c2", "status": "affected", "version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "versionType": "git"}, {"lessThan": "6cba08dc1922140d260cfeb30bbda4ee1bf869d8", "status": "affected", "version": "cc53ce53c86924bfe98a12ea20b7465038a08792", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/nfsd/vfs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.38"}, {"lessThan": "2.6.38", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc1", "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\nnfsd: release path refs on follow_down() error\n\nnfsd_cross_mnt() initializes a local struct path with mntget() and\ndget() before calling follow_down(). On a negative return the error\narm jumps to out without releasing those references:\n\n err = follow_down(&path, follow_flags);\n if (err < 0)\n goto out;\n\nfollow_down() never drops the caller's entry-time refs on any error\nsub-case; for example a pre-cross d_manage() failure leaves path\nuntouched, so the mntget()/dget() taken on entry survive the call.\n\nEvery other early-exit arm in nfsd_cross_mnt() (other-namespace\nreturn, IS_ERR(exp2), and the success tail after the swap) already\ncalls path_put(&path); the err < 0 arm is the lone omission. The\nleak inflates mnt_count and d_count on each failed cross-mount,\nblocking umount and pinning dentries against the shrinker, and is\nreachable by any authenticated NFS client through nfsd_lookup_dentry\nor the NFSv4 READDIR encode path.\n\nFix by calling path_put(&path) before the goto out in the err < 0\narm so the entry-time refs are released on all follow_down() error\nreturns."}], "id": "CVE-2026-89707", "lastModified": "2026-09-11T20:19:58.017", "metrics": {}, "published": "2026-09-11T20:19:58.017", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/194316df81263519156ebe714c4a286bee00e5be"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2bc4343308d85ee4e0dd3877b384306c96f114c2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/467d56fd3ff57447a790c6dc3ede2d02a947d224"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6cba08dc1922140d260cfeb30bbda4ee1bf869d8"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel nfsd: Denial of Service due to reference count leak", "id": "2532441", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532441"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-911", "details": ["A flaw was found in the Linux kernel's nfsd component. An authenticated Network File System (NFS) client can exploit this vulnerability by triggering a failed cross-mount operation through `nfsd_lookup_dentry` or the NFSv4 READDIR encode path. This leads to a reference count leak, which inflates `mnt_count` and `d_count`, blocking unmounting operations and pinning directory entries against the shrinker. This can result in a Denial of Service (DoS) condition."], "name": "CVE-2026-89707", "public_date": "2026-09-11T19:46:23Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89707\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89707\nhttps://git.kernel.org/stable/c/194316df81263519156ebe714c4a286bee00e5be\nhttps://git.kernel.org/stable/c/2bc4343308d85ee4e0dd3877b384306c96f114c2\nhttps://git.kernel.org/stable/c/467d56fd3ff57447a790c6dc3ede2d02a947d224\nhttps://git.kernel.org/stable/c/6cba08dc1922140d260cfeb30bbda4ee1bf869d8"], "threat_severity": "Moderate"}

{"created": "2026-09-12T08:15:07.026618+00:00", "updated": "2026-09-12T08:15:07.026623+00:00", "vendors": [], "weaknesses": ["CWE-668", "CWE-401"]}