Linux Kernel up to 6.6.139/6.12.87/7.0.3 handle_partition_descriptor part_descs_loc[] out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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7.7$5k-$25k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.139/6.12.87/7.0.3 and classified as critical. Affected is the function handle_partition_descriptor. Executing a manipulation of the argument part_descs_loc[] can lead to out-of-bounds write. The identification of this vulnerability is CVE-2026-45991. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.139/6.12.87/7.0.3. It has been declared as critical. This vulnerability affects the function handle_partition_descriptor. The manipulation of the argument part_descs_loc[] with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-45991 since 05/13/2026. The exploitation appears to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/06/2026).

The vulnerability scanner Nessus provides a plugin with the ID 325059 (Debian dla-4665 : affs-modules-6.1.0-48-4kc-malta-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.140, 6.12.88, 7.0.4 or 7.1-rc1 eliminates this vulnerability. Applying the patch 058b451b1039f056d1362c4fec2229e522366ab0/b5597bb83fc37b5b5da74a4453fa920b932cf39a/08fa5d818e5bf53c7ca234d88ba334f32004e9b6/08841b06fa64d8edbd1a21ca6e613420c90cc4b8 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (325059). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 325059
Nessus Name: Debian dla-4665 : affs-modules-6.1.0-48-4kc-malta-di - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.140/6.12.88/7.0.4/7.1-rc1
Patch: 058b451b1039f056d1362c4fec2229e522366ab0/b5597bb83fc37b5b5da74a4453fa920b932cf39a/08fa5d818e5bf53c7ca234d88ba334f32004e9b6/08841b06fa64d8edbd1a21ca6e613420c90cc4b8

Timelineinfo

05/13/2026 CVE reserved
05/27/2026 +14 days Advisory disclosed
05/27/2026 +0 days VulDB entry created
07/06/2026 +40 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-45991 (🔒)
GCVE (CVE): GCVE-0-2026-45991
GCVE (VulDB): GCVE-100-366244

Entryinfo

Created: 05/27/2026 17:19
Updated: 07/06/2026 08:47
Changes: 05/27/2026 17:19 (60), 06/16/2026 17:17 (11), 07/06/2026 08:47 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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