In the Linux kernel, the following vulnerability has been resolved:

udf: reject VAT indexes equal to the entry count

UDF 1.50 virtual partition mapping uses the VAT as an array of physical
block mappings. s_num_entries stores the number of entries in that array,
not the highest valid index. The valid VAT indexes are therefore below
s_num_entries.

udf_get_pblock_virt15() currently rejects only indexes greater than
s_num_entries. A crafted image can request index s_num_entries, pass the
bounds check, and make the kernel read one entry past the allocated VAT table.

Change the check to reject block >= s_num_entries, so the count is handled as
an exclusive upper bound.

A crafted UDF image reproduced this on origin/master commit
0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53 with a KASAN slab-out-of-bounds
report in udf_get_pblock_virt15().

Trail of Bits has a reproducer that triggers kernel panic demonstrating the bug, and can share it if needed.

Project Subscriptions

Vendors Products
Linux Kernel Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4841-1 linux security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 14 Sep 2026 12:30:00 +0000


Sat, 12 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1285
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: udf: reject VAT indexes equal to the entry count UDF 1.50 virtual partition mapping uses the VAT as an array of physical block mappings. s_num_entries stores the number of entries in that array, not the highest valid index. The valid VAT indexes are therefore below s_num_entries. udf_get_pblock_virt15() currently rejects only indexes greater than s_num_entries. A crafted image can request index s_num_entries, pass the bounds check, and make the kernel read one entry past the allocated VAT table. Change the check to reject block >= s_num_entries, so the count is handled as an exclusive upper bound. A crafted UDF image reproduced this on origin/master commit 0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53 with a KASAN slab-out-of-bounds report in udf_get_pblock_virt15(). Trail of Bits has a reproducer that triggers kernel panic demonstrating the bug, and can share it if needed.
Title udf: reject VAT indexes equal to the entry count
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T08:48:16.507Z

Reserved: 2026-09-11T19:38:34.719Z

Link: CVE-2026-89525

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T20:19:35.263

Modified: 2026-10-19T09:17:47.013

Link: CVE-2026-89525

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-11T19:44:06Z

Links: CVE-2026-89525 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T22:30:15Z

Weaknesses