{"api_version":"1","generated_at":"2026-07-04T18:19:02+00:00","cve":"CVE-2026-53341","urls":{"html":"https://cve.report/CVE-2026-53341","api":"https://cve.report/api/cve/CVE-2026-53341.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-53341","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-53341"},"summary":{"title":"fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()\n\nmay_decode_fh() accesses mount::mnt_ns without holding any locks; that\nmeans the mount can concurrently be unmounted, and the mnt_namespace can\nconcurrently be freed after an RCU grace period.\n\nThis race can happens as follows, assuming that the mount point was\ncreated by open_tree(..., OPEN_TREE_CLONE):\n\nthread 1 thread 2 RCU\n __do_sys_open_by_handle_at\n do_handle_open\n handle_to_path\n may_decode_fh\n is_mounted\n [mount::mnt_ns access]\n [mount::mnt_ns access]\n__do_sys_close\n fput_close_sync\n __fput\n dissolve_on_fput\n umount_tree\n class_namespace_excl_destructor\n namespace_unlock\n free_mnt_ns\n mnt_ns_tree_remove\n call_rcu(mnt_ns_release_rcu)\n mnt_ns_release_rcu\n mnt_ns_release\n kfree\n [mnt_namespace::user_ns access] **UAF**\n\nFix it by taking rcu_read_lock() around the mount::mnt_ns access, like\nin __prepend_path().\nAdditionally, document the semantics of mount::mnt_ns, and use WRITE_ONCE()\nfor writers that can race with lockless readers.\n\nThis bug is unreachable unless one of the following is set:\n\n - CONFIG_PREEMPTION\n - CONFIG_RCU_STRICT_GRACE_PERIOD\n\nbecause it requires an RCU grace period to happen during a syscall without\nan explicit preemption.\n\nThis doesn't seem to have interesting security impact; worst-case, it could\nleak the result of an integer comparison to userspace (from the level\ncheck in cap_capable()), cause an endless loop, or crash the kernel by\ndereferencing an invalid address.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-01 14:16:42","updated_at":"2026-07-04 12:17:01"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/15ea8dc42a02259d49dee38a658d40f60fcd75ed","name":"https://git.kernel.org/stable/c/15ea8dc42a02259d49dee38a658d40f60fcd75ed","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/40ab6644b99685755f740b872c00ef40d9aa870e","name":"https://git.kernel.org/stable/c/40ab6644b99685755f740b872c00ef40d9aa870e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/32138633e51e6db59e474765cf93268c92b42888","name":"https://git.kernel.org/stable/c/32138633e51e6db59e474765cf93268c92b42888","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a8ed2c29fcfdac78db96c9da4e659c8a513f2a94","name":"https://git.kernel.org/stable/c/a8ed2c29fcfdac78db96c9da4e659c8a513f2a94","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53341","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53341","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 620c266f394932e5decc4b34683a75dfc59dc2f4 15ea8dc42a02259d49dee38a658d40f60fcd75ed git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 620c266f394932e5decc4b34683a75dfc59dc2f4 32138633e51e6db59e474765cf93268c92b42888 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 620c266f394932e5decc4b34683a75dfc59dc2f4 a8ed2c29fcfdac78db96c9da4e659c8a513f2a94 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 620c266f394932e5decc4b34683a75dfc59dc2f4 40ab6644b99685755f740b872c00ef40d9aa870e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.95 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.36 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.13 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"53341","cve":"CVE-2026-53341","epss":"0.001540000","percentile":"0.049700000","score_date":"2026-07-03","updated_at":"2026-07-04 00:02:18"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/fhandle.c","fs/mount.h","fs/namespace.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"15ea8dc42a02259d49dee38a658d40f60fcd75ed","status":"affected","version":"620c266f394932e5decc4b34683a75dfc59dc2f4","versionType":"git"},{"lessThan":"32138633e51e6db59e474765cf93268c92b42888","status":"affected","version":"620c266f394932e5decc4b34683a75dfc59dc2f4","versionType":"git"},{"lessThan":"a8ed2c29fcfdac78db96c9da4e659c8a513f2a94","status":"affected","version":"620c266f394932e5decc4b34683a75dfc59dc2f4","versionType":"git"},{"lessThan":"40ab6644b99685755f740b872c00ef40d9aa870e","status":"affected","version":"620c266f394932e5decc4b34683a75dfc59dc2f4","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/fhandle.c","fs/mount.h","fs/namespace.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.11"},{"lessThan":"6.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.95","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.36","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.13","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.95","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.36","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.13","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"6.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()\n\nmay_decode_fh() accesses mount::mnt_ns without holding any locks; that\nmeans the mount can concurrently be unmounted, and the mnt_namespace can\nconcurrently be freed after an RCU grace period.\n\nThis race can happens as follows, assuming that the mount point was\ncreated by open_tree(..., OPEN_TREE_CLONE):\n\nthread 1 thread 2 RCU\n __do_sys_open_by_handle_at\n do_handle_open\n handle_to_path\n may_decode_fh\n is_mounted\n [mount::mnt_ns access]\n [mount::mnt_ns access]\n__do_sys_close\n fput_close_sync\n __fput\n dissolve_on_fput\n umount_tree\n class_namespace_excl_destructor\n namespace_unlock\n free_mnt_ns\n mnt_ns_tree_remove\n call_rcu(mnt_ns_release_rcu)\n mnt_ns_release_rcu\n mnt_ns_release\n kfree\n [mnt_namespace::user_ns access] **UAF**\n\nFix it by taking rcu_read_lock() around the mount::mnt_ns access, like\nin __prepend_path().\nAdditionally, document the semantics of mount::mnt_ns, and use WRITE_ONCE()\nfor writers that can race with lockless readers.\n\nThis bug is unreachable unless one of the following is set:\n\n - CONFIG_PREEMPTION\n - CONFIG_RCU_STRICT_GRACE_PERIOD\n\nbecause it requires an RCU grace period to happen during a syscall without\nan explicit preemption.\n\nThis doesn't seem to have interesting security impact; worst-case, it could\nleak the result of an integer comparison to userspace (from the level\ncheck in cap_capable()), cause an endless loop, or crash the kernel by\ndereferencing an invalid address."}],"providerMetadata":{"dateUpdated":"2026-07-04T11:51:08.911Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/15ea8dc42a02259d49dee38a658d40f60fcd75ed"},{"url":"https://git.kernel.org/stable/c/32138633e51e6db59e474765cf93268c92b42888"},{"url":"https://git.kernel.org/stable/c/a8ed2c29fcfdac78db96c9da4e659c8a513f2a94"},{"url":"https://git.kernel.org/stable/c/40ab6644b99685755f740b872c00ef40d9aa870e"}],"title":"fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-53341","datePublished":"2026-07-01T13:32:22.873Z","dateReserved":"2026-06-09T07:44:35.399Z","dateUpdated":"2026-07-04T11:51:08.911Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-01 14:16:42","lastModifiedDate":"2026-07-04 12:17:01","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"53341","Ordinal":"1","Title":"fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh(","CVE":"CVE-2026-53341","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"53341","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nfhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()\n\nmay_decode_fh() accesses mount::mnt_ns without holding any locks; that\nmeans the mount can concurrently be unmounted, and the mnt_namespace can\nconcurrently be freed after an RCU grace period.\n\nThis race can happens as follows, assuming that the mount point was\ncreated by open_tree(..., OPEN_TREE_CLONE):\n\nthread 1 thread 2 RCU\n __do_sys_open_by_handle_at\n do_handle_open\n handle_to_path\n may_decode_fh\n is_mounted\n [mount::mnt_ns access]\n [mount::mnt_ns access]\n__do_sys_close\n fput_close_sync\n __fput\n dissolve_on_fput\n umount_tree\n class_namespace_excl_destructor\n namespace_unlock\n free_mnt_ns\n mnt_ns_tree_remove\n call_rcu(mnt_ns_release_rcu)\n mnt_ns_release_rcu\n mnt_ns_release\n kfree\n [mnt_namespace::user_ns access] **UAF**\n\nFix it by taking rcu_read_lock() around the mount::mnt_ns access, like\nin __prepend_path().\nAdditionally, document the semantics of mount::mnt_ns, and use WRITE_ONCE()\nfor writers that can race with lockless readers.\n\nThis bug is unreachable unless one of the following is set:\n\n - CONFIG_PREEMPTION\n - CONFIG_RCU_STRICT_GRACE_PERIOD\n\nbecause it requires an RCU grace period to happen during a syscall without\nan explicit preemption.\n\nThis doesn't seem to have interesting security impact; worst-case, it could\nleak the result of an integer comparison to userspace (from the level\ncheck in cap_capable()), cause an endless loop, or crash the kernel by\ndereferencing an invalid address.","Type":"Description","Title":"fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh("}]}}}