CVE Catalog

CVE-2026-89525

Low risk· EPSS 7%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

7th percentile - higher than 7% of all known CVEs

Summary

In the Linux kernel UDF filesystem, UDF 1.50 virtual partition mapping uses the VAT as an array of physical block mappings, where s_num_entries stores the number of entries, not the highest valid index. udf_get_pblock_virt15() currently rejects only indexes greater than s_num_entries, so 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.

Risk Assessment

An attacker can supply a crafted UDF image, triggering an out-of-bounds read (slab-out-of-bounds) and potentially a kernel panic or data disclosure. It affects systems mounting untrusted UDF images.

Recommendation

Update the Linux kernel to a version with the fix that changes the check to reject block >= s_num_entries, treating the count as an exclusive upper bound.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS