{"id":"CVE-2026-92499","revision":null,"records":[{"revision":"42bc30b844014bad90a792e854bbf1cf","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-92499","aliases":[],"title":"ext4: validate readdir offset before accessing dirent","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: validate readdir offset before accessing dirent\n\nA corrupted directory can trigger the following KASAN report when\next4_readdir() resumes from an invalid position:\n\n  BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x5ef/0x820\n  Read of size 2 at addr ffff88810a646000 by task repro_linear/509\n\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x53/0x70\n   print_report+0xd0/0x630\n   kasan_report+0xce/0x100\n   __ext4_check_dir_entry+0x5ef/0x820\n   ext4_readdir+0xcde/0x2b70\n   iterate_dir+0x1a1/0x520\n   __x64_sys_getdents64+0x12b/0x220\n   do_syscall_64+0xf9/0x540\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   </TASK>\n\nKASAN reports use-after-free because the out-of-bounds access lands in an\nadjacent freed page. The directory buffer itself is still referenced.\n\next4_dir_llseek() invalidates the directory cookie so that ext4_readdir()\nrescans directory entries from the start of the block. The rescan checks\nonly the lower bound of rec_len before advancing. A corrupted rec_len can\ntherefore place the offset where the block has insufficient space for a\ncomplete directory entry. The rescan itself may dereference that truncated\nentry, or the main loop may pass it to __ext4_check_dir_entry(). The latter\nreads de->rec_len before validating the range. For example:\n\n  block offset  0                           4092  4096\n                |---- de1.rec_len = 4092 -----|----|\n                                               de2.inode\n                                                    | de2.rec_len\n                                                    ^ OOB, reported as UAF\n\nde2 starts at offset 4092 in this 4 KiB block. Its four-byte inode fits in\nthe block, but its rec_len starts at offset 4096 and crosses the boundary.\n\nThe minimum safe length is inode-dependent. Encrypted and casefolded\ndirectory entries need eight additional hash bytes, while a valid metadata\nchecksum tail is only 12 bytes.\n\nCache the metadata checksum feature state and derive the minimum directory\nentry length from the on-disk format. Use it to bound both the rescan and\nthe offset passed to the main loop. Report an offset in a truncated block\ntail and skip the remainder of the block, while continuing to accept an\noffset exactly at the block boundary.","state":0,"publishedAt":"2026-09-17T16:10:13.391+00:00","modifiedAt":"2026-10-19T09:04:05.335+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/ext4/dir.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"ac27a0ec112a089f1a5102bc8dffc79c8c815571\",\n                            \"lessThan\": \"64d445d40e5ea4c4d4d88880db753b370cb69161\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ac27a0ec112a089f1a5102bc8dffc79c8c815571\",\n                            \"lessThan\": \"b4c728577933753180e3e97f08424d5bcaff705e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ac27a0ec112a089f1a5102bc8dffc79c8c815571\",\n                            \"lessThan\": \"bc4b7b0414c33b2c8898eb04386df0d21a13dad8\",\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/ext4/dir.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.19\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.19\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.52\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.6\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/64d445d40e5ea4c4d4d88880db753b370cb69161","https://git.kernel.org/stable/c/b4c728577933753180e3e97f08424d5bcaff705e","https://git.kernel.org/stable/c/bc4b7b0414c33b2c8898eb04386df0d21a13dad8"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-92499","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-92499","identifiers":["CVE-2026-92499"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-3c8e547b28ad4f0fa34b0d9a3442b37e","complete":false,"records":13654,"lastAttemptAt":"2026-11-09T02:21:06.332251+00:00","lastSuccessAt":"2026-11-09T02:21:06.328+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:21:06.328+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13634,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T02:08:49.7164208+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T02:08:49.7164208+00:00","lastSuccessAt":"2026-11-09T02:08:49.9145991+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.9145992+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-5a44a451442747cb81d83104fe1e7771","complete":true,"records":13666,"lastAttemptAt":"2026-11-09T02:08:52.2785198+00:00","lastSuccessAt":"2026-11-09T02:08:52.274+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:52.274+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-09T02:08:49.2635464+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.2635464+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-09T02:08:48.7750517+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:48.7750517+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-3b1150af6d7ada2c07356cbab4ead5224c1485027890f71c71d0742cddf0b9e8","complete":true,"records":3055,"lastAttemptAt":"2026-11-09T02:08:49.6317268+00:00","lastSuccessAt":"2026-11-09T00:02:23.4330288+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.6317268+00:00","snapshotPublishedAt":"2026-11-08T23:17:54+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-f8647d7ba64b1ba0dfdc7130944766d5b36d5b77d18fff0c79e651a4cff3c2b9","complete":true,"records":231293,"lastAttemptAt":"2026-11-09T02:08:49.149268+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.149268+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}