{"id":"CVE-2026-89525","title":"udf: reject VAT indexes equal to the entry count","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nudf: reject VAT indexes equal to the entry count\n\nUDF 1.50 virtual partition mapping uses the VAT as an array of physical\nblock mappings. s_num_entries stores the numbe…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-1285"],"vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f64e01a90326bb85a3cc8aa0199931dc2f15b589","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8a8c1c42a34349a0626d910abbad5a29136446b7","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 19f36c6453cd88fe6d60ef36ab1f1cad8ddf4ce4","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b77b83f5529a26d084d64ece98abd6f0cc86e053","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 9193368408d792cec2057628d87862140fb1ce1c","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b95c33a4e743874f1b0a45bf2aaa4da553552bd1","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1bd7947f1463c21edafa256d0fbec5b99215e2b6","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < cac0cb07f29ccfb373fd4a36c81e908ef3ce608c","Linux 2.6.12"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:48:16.507Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89525","references":[{"url":"https://git.kernel.org/stable/c/f64e01a90326bb85a3cc8aa0199931dc2f15b589"},{"url":"https://git.kernel.org/stable/c/8a8c1c42a34349a0626d910abbad5a29136446b7"},{"url":"https://git.kernel.org/stable/c/19f36c6453cd88fe6d60ef36ab1f1cad8ddf4ce4"},{"url":"https://git.kernel.org/stable/c/b77b83f5529a26d084d64ece98abd6f0cc86e053"},{"url":"https://git.kernel.org/stable/c/9193368408d792cec2057628d87862140fb1ce1c"},{"url":"https://git.kernel.org/stable/c/b95c33a4e743874f1b0a45bf2aaa4da553552bd1"},{"url":"https://git.kernel.org/stable/c/1bd7947f1463c21edafa256d0fbec5b99215e2b6"},{"url":"https://git.kernel.org/stable/c/cac0cb07f29ccfb373fd4a36c81e908ef3ce608c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89525.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89525"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532509"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89525"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89525"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89525.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00184,"epssPercentile":0.07964,"ingestedAt":"2026-09-14T15:23:07.452Z","slug":"CVE-2026-89525","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nudf: reject VAT indexes equal to the entry count\n\nUDF 1.50 virtual partition mapping uses the VAT as an array of physical\nblock mappings. s_num_entries stores the number of entries in that array,\nnot the highest valid index. The valid VAT indexes are therefore below\ns_num_entries.\n\nudf_get_pblock_virt15() currently rejects only indexes greater than\ns_num_entries. A crafted image can request index s_num_entries, pass the\nbounds check, and make the kernel read one entry past the allocated VAT table.\n\nChange the check to reject block >= s_num_entries, so the count is handled as\nan exclusive upper bound.\n\nA crafted UDF image reproduced this on origin/master commit\n0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53 with a KASAN slab-out-of-bounds\nreport in udf_get_pblock_virt15().\n\nTrail of Bits has a reproducer that triggers kernel panic demonstrating the bug, and can share it if needed.\n\n## Affected\n\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f64e01a90326bb85a3cc8aa0199931dc2f15b589`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8a8c1c42a34349a0626d910abbad5a29136446b7`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 19f36c6453cd88fe6d60ef36ab1f1cad8ddf4ce4`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b77b83f5529a26d084d64ece98abd6f0cc86e053`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 9193368408d792cec2057628d87862140fb1ce1c`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < b95c33a4e743874f1b0a45bf2aaa4da553552bd1`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1bd7947f1463c21edafa256d0fbec5b99215e2b6`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < cac0cb07f29ccfb373fd4a36c81e908ef3ce608c`\n- `Linux 2.6.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89525.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":203944,"id":"CVE-2026-89525","ts":1789490230702,"field":"cvss","old":null,"new":"5.5"},{"seq":203943,"id":"CVE-2026-89525","ts":1789490230702,"field":"severity","old":"none","new":"medium"},{"seq":147109,"id":"CVE-2026-89525","ts":1789270195208,"field":"cvss","old":null,"new":"4"},{"seq":147108,"id":"CVE-2026-89525","ts":1789270195208,"field":"severity","old":"none","new":"medium"},{"seq":108856,"id":"CVE-2026-89525","ts":1789183729274,"field":"cvss","old":null,"new":"4"},{"seq":108855,"id":"CVE-2026-89525","ts":1789183729274,"field":"severity","old":"none","new":"medium"}]}