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CVE-2026-45991 is a memory-safety vulnerability in the Linux kernel UDF filesystem implementation. The flaw is in partition descriptor bookkeeping within handle_partition_descriptor() while processing UDF partition descriptors during mount. A crafted UDF image containing repeated partition descriptors can cause duplicate descriptors to be appended repeatedly because appended entries do not record the partition number used for deduplication. This causes num_part_descs to grow incorrectly. When the descriptor table becomes full, the reallocation logic derives capacity from partnum even though insertion is indexed by num_part_descs. If partnum is already aligned to the allocation step, the computed capacity may remain unchanged, and the next append can write past the end of the part_descs_loc[] heap allocation. The issue results in a heap out-of-bounds write in kernel space during filesystem mount processing.
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8 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A specific vulnerability affecting Red Hat Enterprise Linux 10.2 kernel-related packages; the content does not provide technical details beyond listing it in the advisory.
A specific vulnerability affecting Red Hat Enterprise Linux 9 kernel-related packages, referenced in RHSA-2026:57252.
A Linux kernel vulnerability in the UDF filesystem involving partition descriptor append bookkeeping.
Linux kernel UDF filesystem vulnerability involving partition descriptor append bookkeeping.
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Every observed campaign linking this CVE to a named adversary.
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Cross-references every affected SKU, including bundled OEM variants.
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