{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-63800", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.013Z", "datePublished": "2026-07-19T12:02:06.897Z", "dateUpdated": "2026-08-17T04:51:05.578Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:51:05.578Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npNFS: Fix use-after-free in pnfs_update_layout()\n\nWhen hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(),\nthe code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds,\npnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(),\nwhich still references 'lo'. This results in a use-after-free when the\ntracepoint accesses lo's fields.\n\nFix this by moving the tracepoint call before pnfs_put_layout_hdr(lo)." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - A compromised or malicious pNFS NFSv4.1+ metadata server can send CB_LAYOUTRECALL callbacks over the NFSv4 backchannel to force NFS_LAYOUT_RETURN while client file I/O reaches pnfs_update_layout(), exploiting the client from the network in typical enterprise/HPC pNFS deployments.\nAC:L - The attacker controls both sides of the race by issuing layout recalls from the server and driving or waiting for concurrent read/write I/O on the mounted pNFS share; no conditions beyond attacker influence are required once a pNFS session exists.\nPR:N - Exploitation requires no local privileges on the victim client—a remote NFS server with an established pNFS session can trigger the layoutreturn/retry path while any client process performs permitted file I/O on the mount.\nUI:N - No interactive victim action is needed during exploitation; automated workloads, daemons, or batch jobs performing routine I/O on an existing pNFS mount are sufficient to hit the vulnerable code path.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security domain and does not cross a VM, container, or IOMMU boundary on its own.\nC:H - The tracepoint reads freed pnfs_layout_hdr fields (plh_stateid seqid and hash) after pnfs_put_layout_hdr() drops the final reference, giving an attacker-controlled use-after-free read primitive over kernel heap memory.\nI:H - Use-after-free on a refcounted kernel layout object enables heap grooming and further memory corruption for arbitrary kernel writes or control-flow hijacking, not merely a bounded fault.\nA:H - Dereferencing a freed pnfs_layout_hdr in kernel context can cause an oops or panic, and use-after-free corruption reliably threatens system availability even when full exploitation is not attempted." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfs/pnfs.c" ], "versions": [ { "version": "06f58dbc49a23c99e5c0f246879ed16667f7bf8f", "lessThan": "4ad8b9a85dbf57ca532ee9e65ad7e6498bfbbf98", "status": "affected", "versionType": "git" }, { "version": "2c8d5fc37fe2384a9bdb6965443ab9224d46f704", "lessThan": "1f24b8302c77dcaf79c64c073877a3b9f4dd25d2", "status": "affected", "versionType": "git" }, { "version": "2c8d5fc37fe2384a9bdb6965443ab9224d46f704", "lessThan": "9c0fb5c09ae5bd68dc0038692af8127029cb0385", "status": "affected", "versionType": "git" }, { "version": "2c8d5fc37fe2384a9bdb6965443ab9224d46f704", "lessThan": "7e37e9b3e82ade881e1798e2f4fcc54aff7793c1", "status": "affected", "versionType": "git" }, { "version": "2c8d5fc37fe2384a9bdb6965443ab9224d46f704", "lessThan": "2883ddd7542b4437a2ab4908fe2773f690e20889", "status": "affected", "versionType": "git" }, { "version": "2c8d5fc37fe2384a9bdb6965443ab9224d46f704", "lessThan": "200e7637f4d6a1342987045eea72641524f909dc", "status": "affected", "versionType": "git" }, { "version": "2c8d5fc37fe2384a9bdb6965443ab9224d46f704", "lessThan": "9645aaf689aff57427ece3b9fa47d5b5399417f4", "status": "affected", "versionType": "git" }, { "version": "2c8d5fc37fe2384a9bdb6965443ab9224d46f704", "lessThan": "13e198a90ca4050f4bee8a3f23680389a6563ccc", "status": "affected", "versionType": "git" }, { "version": "aa2399f55eff4ec78330bb6fe55f9df53e5cae0c", "status": "affected", "versionType": "git" }, { "version": "5.10.9", "lessThan": "5.10.260", "status": "affected", "versionType": "semver" }, { "version": "5.4.91", "lessThan": "5.5", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfs/pnfs.c" ], "versions": [ { "version": "5.11", "status": "affected" }, { "version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.260", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.211", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.177", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.144", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.95", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.38", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.3", "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": "5.10.9", "versionEndExcluding": "5.10.260" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.211" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.1.177" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.6.144" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.12.95" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.18.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.1.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.91" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4ad8b9a85dbf57ca532ee9e65ad7e6498bfbbf98" }, { "url": "https://git.kernel.org/stable/c/1f24b8302c77dcaf79c64c073877a3b9f4dd25d2" }, { "url": "https://git.kernel.org/stable/c/9c0fb5c09ae5bd68dc0038692af8127029cb0385" }, { "url": "https://git.kernel.org/stable/c/7e37e9b3e82ade881e1798e2f4fcc54aff7793c1" }, { "url": "https://git.kernel.org/stable/c/2883ddd7542b4437a2ab4908fe2773f690e20889" }, { "url": "https://git.kernel.org/stable/c/200e7637f4d6a1342987045eea72641524f909dc" }, { "url": "https://git.kernel.org/stable/c/9645aaf689aff57427ece3b9fa47d5b5399417f4" }, { "url": "https://git.kernel.org/stable/c/13e198a90ca4050f4bee8a3f23680389a6563ccc" } ], "title": "pNFS: Fix use-after-free in pnfs_update_layout()", "x_generator": { "engine": "bippy-1.2.0" } } } }