High 7.8Published May 27, 2026

CVE-2026-45991udf: fix partition descriptor append bookkeeping

Updated under an hour ago (Oct 27, 2026, 4:23 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: udf: fix partition descriptor append bookkeeping Mounting a crafted UDF image with repeated partition descriptors can trigger a heap out-of-bounds write in part_descs_loc[]. handle_partition_descriptor() deduplicates entries by partition number, but appended slots never record partnum. As a result duplicate Partition Descriptors are appended repeatedly and num_part_descs keeps growing. Once the table is full, the growth path still sizes the allocation from partnum even though inserts are indexed by num_part_descs. If partnum is already aligned to PART_DESC_ALLOC_STEP, ALIGN(partnum, step) can keep the old capacity and the next append writes past the end of the table. Store partnum in the appended slot and size growth from the next append count so deduplication and capacity tracking follow the same model.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-787
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before ad3c0c4400686f6f37b382aaa48fac2b9aefccbe; from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 68013a9bd4c01acd42073715f00e1a1992f089ee; from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before e8474cfbac9ada2cdaa4eaedec22aadfa0f58559; from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 058b451b1039f056d1362c4fec2229e522366ab0; from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before b5597bb83fc37b5b5da74a4453fa920b932cf39a; from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 73df74544b55241dca5dd788523e6f5f10bd2b9b; from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 08fa5d818e5bf53c7ca234d88ba334f32004e9b6; from ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 08841b06fa64d8edbd1a21ca6e613420c90cc4b8; and 2 more ranges	CNA record
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name)	all versions	CISA ADP
linux linux_kernel linux:linux_kernel	from 4.18.7 before 4.19; from 4.19.1 before 6.6.140; from 6.7 before 6.12.88; from 6.13 before 7.0.4; 4.19; 4.19; 4.19; 4.19; and 4 more ranges	NVD

References

References

https://git.kernel.org/stable/c/ad3c0c4400686f6f37b382aaa48fac2b9aefccbe
https://git.kernel.org/stable/c/68013a9bd4c01acd42073715f00e1a1992f089ee
https://git.kernel.org/stable/c/e8474cfbac9ada2cdaa4eaedec22aadfa0f58559
https://git.kernel.org/stable/c/058b451b1039f056d1362c4fec2229e522366ab0	patch
https://git.kernel.org/stable/c/b5597bb83fc37b5b5da74a4453fa920b932cf39a	patch
https://git.kernel.org/stable/c/73df74544b55241dca5dd788523e6f5f10bd2b9b
https://git.kernel.org/stable/c/08fa5d818e5bf53c7ca234d88ba334f32004e9b6	patch
https://git.kernel.org/stable/c/08841b06fa64d8edbd1a21ca6e613420c90cc4b8	patch
https://cert-portal.siemens.com/productcert/html/ssa-784472.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.