7.8
HIGH
CVSS 3.1
CVE-2026-64324
udf: validate free block extents against the partition length
Overview
Description
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.
Details
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework
for assessing the severity of vulnerabilities in software and systems.
We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
Apply kernel updates to fix an out-of-bounds read and kernel panic vulnerability.
- Update the Linux kernel to the latest stable version.
- Ensure UDF filesystem drivers are properly validated.
- Verify partition length checks are correctly implemented.
- Apply vendor-specific patches for the UDF module.
References
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64324.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64324 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64324
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64324 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64324 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '934f815345c09c290a9b9a9cfdddc203ec2117e8', 'lessThan': 'fdd6229d2ae9914c1f25d1041db0f4f312a4fa76', 'versionType': 'git'}, {'status': 'affected', 'version': '22cc7323f090646c8cfb5939e6f15bdc2ed3fd27', 'lessThan': 'b54aee5652fcd7c23a0904a4623ec462c3edc70c', 'versionType': 'git'}, {'status': 'affected', 'version': '7c4fa9ebfce69619d132fe703dc2e2cf62a13723', 'lessThan': '12af328d2ee8d68e81ba612246d0b54b22d23e1f', 'versionType': 'git'}, {'status': 'affected', 'version': '5cc9745e2ea11aef7d5c9a42bc36f6cd3e1b4cc3', 'lessThan': 'fb49099206c5c57af28a157249fa7bcb5518f99e', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '9442d75429b0c556292a7454fe888d54259f5240', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '335202ab25b01fdd45889ff25eab70864686dea3', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': 'be87de7789a82a030a4896bc7683415ec9fa6f2b', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '5f0419457f89dce1a3f1c8e62a3adf2f39ab8168', 'versionType': 'git'}, {'status': 'affected', 'version': '097420e48e30f51e8f4f650b5c946f5af63ec1a3', 'versionType': 'git'}, {'status': 'affected', 'version': '5def895b42ef16a2da6402818cba8d7ec8ede1ef', 'versionType': 'git'}, {'status': 'affected', 'version': '05fb2bf477d3fe5421bd4cb699574737f52bd88b', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.224', 'lessThan': '5.10.261', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.165', 'lessThan': '5.15.212', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.1.105', 'lessThan': '6.1.178', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.6.46', 'lessThan': '6.6.145', 'versionType': 'semver'}, {'status': 'affected', 'version': '4.19.320', 'lessThan': '4.20', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.4.282', 'lessThan': '5.5', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.10.5', 'lessThan': '6.11', 'versionType': 'semver'}], 'programFiles': ['fs/udf/balloc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.11'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.11', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/udf/balloc.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '934f815345c09c290a9b9a9cfdddc203ec2117e8', 'lessThan': 'fdd6229d2ae9914c1f25d1041db0f4f312a4fa76', 'versionType': 'git'}, {'status': 'affected', 'version': '22cc7323f090646c8cfb5939e6f15bdc2ed3fd27', 'lessThan': 'b54aee5652fcd7c23a0904a4623ec462c3edc70c', 'versionType': 'git'}, {'status': 'affected', 'version': '7c4fa9ebfce69619d132fe703dc2e2cf62a13723', 'lessThan': '12af328d2ee8d68e81ba612246d0b54b22d23e1f', 'versionType': 'git'}, {'status': 'affected', 'version': '5cc9745e2ea11aef7d5c9a42bc36f6cd3e1b4cc3', 'lessThan': 'fb49099206c5c57af28a157249fa7bcb5518f99e', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '9442d75429b0c556292a7454fe888d54259f5240', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '335202ab25b01fdd45889ff25eab70864686dea3', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': 'be87de7789a82a030a4896bc7683415ec9fa6f2b', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '5f0419457f89dce1a3f1c8e62a3adf2f39ab8168', 'versionType': 'git'}, {'status': 'affected', 'version': '097420e48e30f51e8f4f650b5c946f5af63ec1a3', 'versionType': 'git'}, {'status': 'affected', 'version': '5def895b42ef16a2da6402818cba8d7ec8ede1ef', 'versionType': 'git'}, {'status': 'affected', 'version': '05fb2bf477d3fe5421bd4cb699574737f52bd88b', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.224', 'lessThan': '5.10.261', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.165', 'lessThan': '5.15.212', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.1.105', 'lessThan': '6.1.178', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.6.46', 'lessThan': '6.6.145', 'versionType': 'semver'}, {'status': 'affected', 'version': '4.19.320', 'lessThan': '4.20', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.4.282', 'lessThan': '5.5', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.10.5', 'lessThan': '6.11', 'versionType': 'semver'}], 'programFiles': ['fs/udf/balloc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.11'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.11', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/udf/balloc.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '934f815345c09c290a9b9a9cfdddc203ec2117e8', 'lessThan': 'fdd6229d2ae9914c1f25d1041db0f4f312a4fa76', 'versionType': 'git'}, {'status': 'affected', 'version': '22cc7323f090646c8cfb5939e6f15bdc2ed3fd27', 'lessThan': 'b54aee5652fcd7c23a0904a4623ec462c3edc70c', 'versionType': 'git'}, {'status': 'affected', 'version': '7c4fa9ebfce69619d132fe703dc2e2cf62a13723', 'lessThan': '12af328d2ee8d68e81ba612246d0b54b22d23e1f', 'versionType': 'git'}, {'status': 'affected', 'version': '5cc9745e2ea11aef7d5c9a42bc36f6cd3e1b4cc3', 'lessThan': 'fb49099206c5c57af28a157249fa7bcb5518f99e', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '9442d75429b0c556292a7454fe888d54259f5240', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '335202ab25b01fdd45889ff25eab70864686dea3', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': 'be87de7789a82a030a4896bc7683415ec9fa6f2b', 'versionType': 'git'}, {'status': 'affected', 'version': '56e69e59751d20993f243fb7dd6991c4e522424c', 'lessThan': '5f0419457f89dce1a3f1c8e62a3adf2f39ab8168', 'versionType': 'git'}, {'status': 'affected', 'version': '097420e48e30f51e8f4f650b5c946f5af63ec1a3', 'versionType': 'git'}, {'status': 'affected', 'version': '5def895b42ef16a2da6402818cba8d7ec8ede1ef', 'versionType': 'git'}, {'status': 'affected', 'version': '05fb2bf477d3fe5421bd4cb699574737f52bd88b', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.224', 'lessThan': '5.10.261', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.165', 'lessThan': '5.15.212', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.1.105', 'lessThan': '6.1.178', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.6.46', 'lessThan': '6.6.145', 'versionType': 'semver'}, {'status': 'affected', 'version': '4.19.320', 'lessThan': '4.20', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.4.282', 'lessThan': '5.5', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.10.5', 'lessThan': '6.11', 'versionType': 'semver'}], 'programFiles': ['fs/udf/balloc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.11'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.11', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/udf/balloc.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/12af328d2ee8d68e81ba612246d0b54b22d23e1f Added Reference https://git.kernel.org/stable/c/335202ab25b01fdd45889ff25eab70864686dea3 Added Reference https://git.kernel.org/stable/c/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168 Added Reference https://git.kernel.org/stable/c/9442d75429b0c556292a7454fe888d54259f5240 Added Reference https://git.kernel.org/stable/c/b54aee5652fcd7c23a0904a4623ec462c3edc70c Added Reference https://git.kernel.org/stable/c/be87de7789a82a030a4896bc7683415ec9fa6f2b Added Reference https://git.kernel.org/stable/c/fb49099206c5c57af28a157249fa7bcb5518f99e Added Reference https://git.kernel.org/stable/c/fdd6229d2ae9914c1f25d1041db0f4f312a4fa76
EPSS is a daily estimate of the probability of exploitation activity
being observed over the next 30 days. Following chart shows the EPSS
score history of the vulnerability.