{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-46124", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.098Z", "datePublished": "2026-05-28T09:35:38.887Z", "dateUpdated": "2026-08-05T12:29:53.831Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:29:53.831Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nisofs: validate block number from NFS file handle in isofs_export_iget\n\nisofs_fh_to_dentry() and isofs_fh_to_parent() pass an attacker-\ncontrolled block number (ifid->block or ifid->parent_block) from\nthe NFS file handle to isofs_export_iget(), which only rejects\nblock == 0 before calling isofs_iget() and ultimately sb_bread().\nA crafted file handle with fh_len sufficient to pass the check\nadded by commit 0405d4b63d08 (\"isofs: Prevent the use of too small\nfid\") can still drive the server to read any in-range block on the\nbacking device as if it were an iso_directory_record. That earlier\nfix was assigned CVE-2025-37780.\n\nsb_bread() on an out-of-range block returns NULL cleanly via the\nEIO path, so there is no memory-safety violation. For in-range\nreads of adjacent-partition data on the same block device, the\nunrelated bytes end up in iso_inode_info fields that reach the NFS\nclient as dentry metadata. The deployment surface (isofs exported\nover NFS from loop-mounted images) is narrow and requires an\nauthenticated NFS peer, but the malformed-file-handle class is\nreportable as hardening next to the existing CVE-2025-37780 fix.\n\nReject block >= ISOFS_SB(sb)->s_nzones in isofs_export_iget() so\nthe check covers both isofs_fh_to_dentry() and isofs_fh_to_parent()\ncall sites with a single line." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable code is reached when nfsd decodes an attacker-supplied NFS file handle (exportfs_decode_fh → isofs_fh_to_dentry), so a remote NFS client triggers it over the network (TCP/UDP 2049).\nAC:L - The attacker fully controls the block field in the file handle and the read is deterministic; no race or uncontrollable memory layout is involved.\nPR:N - The decode runs before per-user permission checks, and the realistic deployment (a read-only ISO exported to a subnet via default AUTH_SYS) lets any permitted network peer craft handles without credentials.\nUI:N - The NFS server processes the crafted request automatically; no victim action is required at attack time beyond the pre-existing export.\nS:U - The impact stays within the kernel filesystem/NFS security authority; no cross-authority boundary (VM, IOMMU, sandbox) is crossed.\nC:H - An out-of-bounds (cross-partition) read of arbitrary in-range blocks on the backing device is disclosed to the NFS client as inode metadata, and is not bounded to a few bytes since the attacker can probe blocks across the device.\nI:N - isofs is mounted strictly read-only and the commit confirms no memory-safety violation, so the attacker cannot modify any data or kernel memory.\nA:N - Out-of-range reads return NULL cleanly via the EIO path and in-range parsing is bounded; the commit and maintainer explicitly confirm no crash, hang, or memory-safety fault." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/isofs/export.c" ], "versions": [ { "version": "5e7de55602c61c8ff28db075cc49c8dd6989d7e0", "lessThan": "ee0024f5a7e3c73aa253869fae9650ae054093ca", "status": "affected", "versionType": "git" }, { "version": "63d5a3e207bf315a32c7d16de6c89753a759f95a", "lessThan": "31dbb4ba0f719ae7774e4c0c95172c9bf81692f5", "status": "affected", "versionType": "git" }, { "version": "0fdafdaef796816a9ed0fd7ac812932d569d9beb", "lessThan": "908a76f0b1038035e6ebb4f2293ce079f92e0a02", "status": "affected", "versionType": "git" }, { "version": "952e7a7e317f126d0a2b879fc531b716932d5ffa", "lessThan": "bb0988ed4f2e26d59bbb58f644cb3a55b7521e21", "status": "affected", "versionType": "git" }, { "version": "56dfffea9fd3be0b3795a9ca6401e133a8427e0b", "lessThan": "0a1af74ae2177bda3aee0837a0546309aa539d0d", "status": "affected", "versionType": "git" }, { "version": "0405d4b63d082861f4eaff9d39c78ee9dc34f845", "lessThan": "afbafeddf23db13fe2edb2d5c0bf4bbb13d7881b", "status": "affected", "versionType": "git" }, { "version": "0405d4b63d082861f4eaff9d39c78ee9dc34f845", "lessThan": "4c721a1d9b3c4fcaf59cc9b2281e3ec5a043e1a6", "status": "affected", "versionType": "git" }, { "version": "0405d4b63d082861f4eaff9d39c78ee9dc34f845", "lessThan": "24376458138387fb251e782e624c7776e9826796", "status": "affected", "versionType": "git" }, { "version": "ee01a309ebf598be1ff8174901ed6e91619f1749", "status": "affected", "versionType": "git" }, { "version": "007124c896e7d4614ac1f6bd4dedb975c35a2a8e", "status": "affected", "versionType": "git" }, { "version": "5.10.237", "lessThan": "5.10.258", "status": "affected", "versionType": "semver" }, { "version": "5.15.181", "lessThan": "5.15.209", "status": "affected", "versionType": "semver" }, { "version": "6.1.135", "lessThan": "6.1.175", "status": "affected", "versionType": "semver" }, { "version": "6.6.88", "lessThan": "6.6.140", "status": "affected", "versionType": "semver" }, { "version": "6.12.25", "lessThan": "6.12.88", "status": "affected", "versionType": "semver" }, { "version": "5.4.293", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "6.14.4", "lessThan": "6.15", "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/isofs/export.c" ], "versions": [ { "version": "6.15", "status": "affected" }, { "version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.88", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.30", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.7", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "5.10.237", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.181", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.135", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.88", "versionEndExcluding": "6.6.140" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.25", "versionEndExcluding": "6.12.88" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "6.18.30" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.0.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.293" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ee0024f5a7e3c73aa253869fae9650ae054093ca" }, { "url": "https://git.kernel.org/stable/c/31dbb4ba0f719ae7774e4c0c95172c9bf81692f5" }, { "url": "https://git.kernel.org/stable/c/908a76f0b1038035e6ebb4f2293ce079f92e0a02" }, { "url": "https://git.kernel.org/stable/c/bb0988ed4f2e26d59bbb58f644cb3a55b7521e21" }, { "url": "https://git.kernel.org/stable/c/0a1af74ae2177bda3aee0837a0546309aa539d0d" }, { "url": "https://git.kernel.org/stable/c/afbafeddf23db13fe2edb2d5c0bf4bbb13d7881b" }, { "url": "https://git.kernel.org/stable/c/4c721a1d9b3c4fcaf59cc9b2281e3ec5a043e1a6" }, { "url": "https://git.kernel.org/stable/c/24376458138387fb251e782e624c7776e9826796" } ], "title": "isofs: validate block number from NFS file handle in isofs_export_iget", "x_generator": { "engine": "bippy-1.2.0" } } } }