{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-74618",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-15T05:44:03.921Z",
        "datePublished": "2026-08-22T15:32:02.778Z",
        "dateUpdated": "2026-08-22T15:32:02.778Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-22T15:32:02.778Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbinfmt_misc: don't warn when the mount is completed from another user namespace\n\nfsopen() records the caller's user namespace in fc->user_ns and hands\nback an ordinary file descriptor. Nothing ties the task that calls\nfsconfig(FSCONFIG_CMD_CREATE) to the task that created the context. The\nfd is inherited across fork() and exec() and it can be passed over a\nunix socket.\n\nCompleting a context from another user namespace is allowed on purpose.\nvfs_cmd_create() authorizes the create with mount_capable(), which for\nFS_USERNS_MOUNT checks ns_capable(fc->user_ns, CAP_SYS_ADMIN), and that\nsucceeds for a task holding CAP_SYS_ADMIN in an ancestor of fc->user_ns.\nSo an unprivileged task can reach the WARN_ON() in bm_fill_super():\ncreate a user and a mount namespace in a child, call\nfsopen(\"binfmt_misc\") there, send the fscontext fd to the parent and let\nthe parent issue FSCONFIG_CMD_CREATE. Both namespaces come from a plain\nunshare(1) and no capability is needed anywhere:\n\n  WARNING: fs/binfmt_misc.c:938 at bm_fill_super+0xa2/0xc0 [binfmt_misc]\n  CPU: 15 UID: 1000 PID: 3243382 Comm: fswarn\n  Call Trace:\n   get_tree_keyed+0x7d/0xb0\n   bm_get_tree+0x34/0x90 [binfmt_misc]\n   vfs_get_tree+0x2a/0x100\n   vfs_cmd_create+0x60/0xf0\n   __do_sys_fsconfig+0x4b2/0x500\n\nThe child needs the mount namespace because fsopen() itself gates on\nmay_mount(), which asks for CAP_SYS_ADMIN in the user namespace owning\nthe caller's mount namespace. fsconfig() doesn't repeat that check.\n\nIt is a WARN_ON() and not a WARN_ON_ONCE(), so the condition can be\nraised in a loop to taint the kernel and flood the log, and it panics a\nkernel booted with panic_on_warn.\n\nKeep refusing the mount and stop warning about it. Nothing in\nbm_fill_super() depends on the two namespaces matching, it derives\neverything from sb->s_user_ns."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/binfmt_misc.c"
                    ],
                    "versions": [
                        {
                            "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
                            "lessThan": "37cf5cf1320a84a17225a1690547b8a0812ca94e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
                            "lessThan": "24e95a24f151ce40d5fc1b3a6cefbcda8ded736c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
                            "lessThan": "047f927f54c6c17593e93aafe82dcb7acdda2a71",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
                            "lessThan": "79fdf39f1a31f88cb3833b6f8091fbf6acdca2c6",
                            "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/binfmt_misc.c"
                    ],
                    "versions": [
                        {
                            "version": "6.7",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.7",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.104",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.45",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.9",
                            "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": "6.7",
                                    "versionEndExcluding": "6.12.104"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "6.18.45"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "7.1.9"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.7",
                                    "versionEndExcluding": "7.2"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/37cf5cf1320a84a17225a1690547b8a0812ca94e"
                },
                {
                    "url": "https://git.kernel.org/stable/c/24e95a24f151ce40d5fc1b3a6cefbcda8ded736c"
                },
                {
                    "url": "https://git.kernel.org/stable/c/047f927f54c6c17593e93aafe82dcb7acdda2a71"
                },
                {
                    "url": "https://git.kernel.org/stable/c/79fdf39f1a31f88cb3833b6f8091fbf6acdca2c6"
                }
            ],
            "title": "binfmt_misc: don't warn when the mount is completed from another user namespace",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}