Linux Kernel up to 7.1.3 UDF udf_free_blocks/load_block_bitmap s_block_bitmap out-of-bounds

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4.8	$0-$5k	2.33-

Summaryinfo

A vulnerability labeled as problematic has been found in Linux Kernel up to 7.1.3. Affected by this issue is the function udf_free_blocks/load_block_bitmap of the component UDF. Such manipulation of the argument s_block_bitmap leads to out-of-bounds. This vulnerability is referenced as CVE-2026-64324. The attack can only be performed from a local environment. No exploit is available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.1.3. It has been rated as problematic. Affected by this issue is the function udf_free_blocks/load_block_bitmap of the component UDF. The manipulation of the argument s_block_bitmap with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: udf: validate free block extents against the partition length udf_free_blocks() checks the logical block number and count against the partition length, but drops the extent offset from that final bound. A crafted extent can pass the guard while logicalBlockNum + offset + count points past the partition, which later indexes past the space bitmap array. A single ftruncate(2) on a file backed by such an extent reliably panics the kernel. This is a local availability issue. On desktop systems where UDisks/polkit allows the active user to mount removable UDF media without CAP_SYS_ADMIN, an unprivileged local user can supply the crafted filesystem and trigger the panic by truncating a writable file on it. Systems that require root or CAP_SYS_ADMIN to mount the image have a higher prerequisite. No confidentiality or integrity impact is claimed: the reproduced primitive is an out-of-bounds read of a bitmap pointer slot followed by a kernel panic. Use the already computed logicalBlockNum + offset + count value for the partition length check. Also make load_block_bitmap() reject an out-of-range block group before indexing s_block_bitmap[], so corrupted callers cannot walk past the flexible array.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-64324 since 07/19/2026. The exploitation is known to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

Upgrading to version 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch fdd6229d2ae9914c1f25d1041db0f4f312a4fa76/b54aee5652fcd7c23a0904a4623ec462c3edc70c/12af328d2ee8d68e81ba612246d0b54b22d23e1f/fb49099206c5c57af28a157249fa7bcb5518f99e/9442d75429b0c556292a7454fe888d54259f5240/335202ab25b01fdd45889ff25eab70864686dea3/be87de7789a82a030a4896bc7683415ec9fa6f2b/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.260
• 5.15.211
• 6.1.177
• 6.6.144
• 6.12.0
• 6.12.1
• 6.12.2
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• 6.12.93
• 6.12.94
• 6.12.95
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
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• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.8

VulDB Base Score: 5.0
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.261/5.15.212/6.1.178/6.6.145/6.12.96/6.18.39/7.1.4/7.2-rc1
Patch: fdd6229d2ae9914c1f25d1041db0f4f312a4fa76/b54aee5652fcd7c23a0904a4623ec462c3edc70c/12af328d2ee8d68e81ba612246d0b54b22d23e1f/fb49099206c5c57af28a157249fa7bcb5518f99e/9442d75429b0c556292a7454fe888d54259f5240/335202ab25b01fdd45889ff25eab70864686dea3/be87de7789a82a030a4896bc7683415ec9fa6f2b/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64324 (🔒)
GCVE (CVE): GCVE-0-2026-64324
GCVE (VulDB): GCVE-100-383120

Entryinfo

Created: 07/25/2026 15:30
Changes: 07/25/2026 15:30 (60)
Complete: 🔍
Cache ID: 216::103

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