{"id":"CVE-2026-64296","revision":"1366c8725b0c48058dc2c5cb84bde694","records":[{"revision":"1366c8725b0c48058dc2c5cb84bde694","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-64296","aliases":[],"title":"exfat: bound uniname advance in exfat_find_dir_entry()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nexfat: bound uniname advance in exfat_find_dir_entry()\n\nIn exfat_find_dir_entry(), each TYPE_EXTEND (file name) entry advances the\noutput pointer by a fixed amount while the loop guard only tracks the\naccumulated name length:\n\n\tif (++order == 2)\n\t\tuniname = p_uniname->name;\n\telse\n\t\tuniname += EXFAT_FILE_NAME_LEN;\n\tlen = exfat_extract_uni_name(ep, entry_uniname);\n\tname_len += len;\n\tunichar = *(uniname+len);\n\t*(uniname+len) = 0x0;\n\nuniname grows by EXFAT_FILE_NAME_LEN (15) per name entry, but name_len\ngrows only by the actual extracted length, which is shorter when a name\nfragment contains an early NUL.  The only guard is\n`name_len >= MAX_NAME_LENGTH`, so a crafted directory with many short\nname fragments lets uniname run far past the\np_uniname->name[MAX_NAME_LENGTH + 3] buffer while name_len stays small,\ncausing an out-of-bounds read and write at *(uniname+len).\n\nThe sibling extractor exfat_get_uniname_from_ext_entry() already stops\non a short fragment (the lockstep `len != EXFAT_FILE_NAME_LEN` guard\nadded in commit d42334578eba (\"exfat: check if filename entries exceeds\nmax filename length\")); exfat_find_dir_entry() never got the\nequivalent.  Track the per-entry write offset as a count and reject a\nfragment once the offset, or the offset plus the extracted length, would\nexceed MAX_NAME_LENGTH, before forming the output pointer.","state":0,"publishedAt":"2026-07-25T08:49:33.847+00:00","modifiedAt":"2026-10-19T20:38:22.402+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/exfat/dir.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"72a2589d82eb001c94b74bcfe6f9a599bd9bef60\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"fae76a94b35ee8c0e2eb6f64caca01d75c6d34e4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"cf85180b8a015029ee147694eaf4e0b3537e9432\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"ce4736c1e6c4cfbf1ac409a8c328a0b69546c9a0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"727bf7783a2936ffd55c628dddfd69343e511dcf\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"33c0b96d7e1672be1de0053786637ea46fb81507\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"c8e041c68c0bbb73aa62371ee63947bb6949d8b2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ca06197382bde0a3bc20215595d1c9ce20c6e341\",\n                            \"lessThan\": \"3a1230e7b043c62737b05a3e9275ca83a43ad20a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/exfat/dir.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.7\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.7\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.96\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.39\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.4\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/72a2589d82eb001c94b74bcfe6f9a599bd9bef60","https://git.kernel.org/stable/c/fae76a94b35ee8c0e2eb6f64caca01d75c6d34e4","https://git.kernel.org/stable/c/cf85180b8a015029ee147694eaf4e0b3537e9432","https://git.kernel.org/stable/c/ce4736c1e6c4cfbf1ac409a8c328a0b69546c9a0","https://git.kernel.org/stable/c/727bf7783a2936ffd55c628dddfd69343e511dcf","https://git.kernel.org/stable/c/33c0b96d7e1672be1de0053786637ea46fb81507","https://git.kernel.org/stable/c/c8e041c68c0bbb73aa62371ee63947bb6949d8b2","https://git.kernel.org/stable/c/3a1230e7b043c62737b05a3e9275ca83a43ad20a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64296","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-64296","identifiers":["CVE-2026-64296"]},"retained":false,"historicalAffected":[]}],"coverage":[]}