High severity · published May 27, 2026
CVE-2026-45991
udf: fix partition descriptor append bookkeeping
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
4.18.7 before 4.19; 4.19.1 before 6.6.140; 6.7 before 6.12.88; 6.13 before 7.0.4; 4.19; 4.19; +6 more · source: NVD
LI
Linux · Linux
ee4af50ca94f58afc3532662779b9cf80bbe27c8 before ad3c0c4400686f6f37b382aaa48fac2b9aefccbe; ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 68013a9bd4c01acd42073715f00e1a1992f089ee; ee4af50ca94f58afc3532662779b9cf80bbe27c8 before e8474cfbac9ada2cdaa4eaedec22aadfa0f58559; ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 058b451b1039f056d1362c4fec2229e522366ab0; ee4af50ca94f58afc3532662779b9cf80bbe27c8 before b5597bb83fc37b5b5da74a4453fa920b932cf39a; ee4af50ca94f58afc3532662779b9cf80bbe27c8 before 73df74544b55241dca5dd788523e6f5f10bd2b9b; +5 more · source: vendor
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45991
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-45991
Patch
https://git.kernel.org/stable/c/058b451b1039f056d1362c4fec2229e522366ab0
Patch
https://git.kernel.org/stable/c/08841b06fa64d8edbd1a21ca6e613420c90cc4b8
Patch
https://git.kernel.org/stable/c/08fa5d818e5bf53c7ca234d88ba334f32004e9b6
git.kernel.org
https://git.kernel.org/stable/c/68013a9bd4c01acd42073715f00e1a1992f089ee
git.kernel.org
https://git.kernel.org/stable/c/73df74544b55241dca5dd788523e6f5f10bd2b9b
git.kernel.org
https://git.kernel.org/stable/c/ad3c0c4400686f6f37b382aaa48fac2b9aefccbe
More from Kernel
9.8
CVE-2025-39682
tls: fix handling of zero-length records on the rx_list
8.8
CVE-2026-53266
netfilter: bridge: make ebt_snat ARP rewrite writable
8.8
CVE-2013-6282
Linux Kernel Improper Input Validation Vulnerability
8.4
CVE-2022-0185
Linux Kernel Heap-Based Buffer Overflow Vulnerability
8.4
CVE-2013-2094
Linux Kernel Privilege Escalation Vulnerability
