Vulnerability-Lookup

CVE-2026-64324 (GCVE-0-2026-64324)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-07-27 04:59

Title

udf: validate free block extents against the partition length

Summary

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.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

8 references

URL	Tags
https://git.kernel.org/stable/c/fdd6229d2ae9914c1…
https://git.kernel.org/stable/c/b54aee5652fcd7c23…
https://git.kernel.org/stable/c/12af328d2ee8d68e8…
https://git.kernel.org/stable/c/fb49099206c5c57af…
https://git.kernel.org/stable/c/9442d75429b0c5562…
https://git.kernel.org/stable/c/335202ab25b01fdd4…
https://git.kernel.org/stable/c/be87de7789a82a030…
https://git.kernel.org/stable/c/5f0419457f89dce1a…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 934f815345c09c290a9b9a9cfdddc203ec2117e8 , < fdd6229d2ae9914c1f25d1041db0f4f312a4fa76 (git) Affected: 22cc7323f090646c8cfb5939e6f15bdc2ed3fd27 , < b54aee5652fcd7c23a0904a4623ec462c3edc70c (git) Affected: 7c4fa9ebfce69619d132fe703dc2e2cf62a13723 , < 12af328d2ee8d68e81ba612246d0b54b22d23e1f (git) Affected: 5cc9745e2ea11aef7d5c9a42bc36f6cd3e1b4cc3 , < fb49099206c5c57af28a157249fa7bcb5518f99e (git) Affected: 56e69e59751d20993f243fb7dd6991c4e522424c , < 9442d75429b0c556292a7454fe888d54259f5240 (git) Affected: 56e69e59751d20993f243fb7dd6991c4e522424c , < 335202ab25b01fdd45889ff25eab70864686dea3 (git) Affected: 56e69e59751d20993f243fb7dd6991c4e522424c , < be87de7789a82a030a4896bc7683415ec9fa6f2b (git) Affected: 56e69e59751d20993f243fb7dd6991c4e522424c , < 5f0419457f89dce1a3f1c8e62a3adf2f39ab8168 (git) Affected: 097420e48e30f51e8f4f650b5c946f5af63ec1a3 (git) Affected: 5def895b42ef16a2da6402818cba8d7ec8ede1ef (git) Affected: 05fb2bf477d3fe5421bd4cb699574737f52bd88b (git) Affected: 5.10.224 , < 5.10.261 (semver) Affected: 5.15.165 , < 5.15.212 (semver) Affected: 6.1.105 , < 6.1.178 (semver) Affected: 6.6.46 , < 6.6.145 (semver) Affected: 4.19.320 , < 4.20 (semver) Affected: 5.4.282 , < 5.5 (semver) Affected: 6.10.5 , < 6.11 (semver)
Linux	Linux	Affected: 6.11 Unaffected: 0 , < 6.11 (semver) Unaffected: 5.10.261 , ≤ 5.10.* (semver) Unaffected: 5.15.212 , ≤ 5.15.* (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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      "title": "udf: validate free block extents against the partition length",
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On desktop\\nsystems where UDisks/polkit allows the active user to mount removable\\nUDF media without CAP_SYS_ADMIN, an unprivileged local user can supply\\nthe crafted filesystem and trigger the panic by truncating a writable\\nfile on it.  Systems that require root or CAP_SYS_ADMIN to mount the\\nimage have a higher prerequisite.\\n\\nNo confidentiality or integrity impact is claimed: the reproduced\\nprimitive is an out-of-bounds read of a bitmap pointer slot followed by\\na kernel panic.\\n\\nUse the already computed logicalBlockNum + offset + count value for the\\npartition length check.  Also make load_block_bitmap() reject an\\nout-of-range block group before indexing s_block_bitmap[], so corrupted\\ncallers cannot walk past the flexible array.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/udf/balloc.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"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\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/udf/balloc.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.11\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.11\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.261\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.212\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.178\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.145\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.96\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.39\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.4\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/12af328d2ee8d68e81ba612246d0b54b22d23e1f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/335202ab25b01fdd45889ff25eab70864686dea3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9442d75429b0c556292a7454fe888d54259f5240\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b54aee5652fcd7c23a0904a4623ec462c3edc70c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/be87de7789a82a030a4896bc7683415ec9fa6f2b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fb49099206c5c57af28a157249fa7bcb5518f99e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fdd6229d2ae9914c1f25d1041db0f4f312a4fa76\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T16:45:42Z",
      "cve": "CVE-2026-64324",
      "id": "CVE-2026-64324",
      "initial_release_date": "2026-07-25T16:45:42Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64324",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64324.json",
      "version": "2"
    }
  }
}

GHSA-MPF7-XMX2-FRHW

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-27 06:30

Details

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.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64324"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:13Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nudf: validate free block extents against the partition length\n\nudf_free_blocks() checks the logical block number and count against the\npartition length, but drops the extent offset from that final bound.  A\ncrafted extent can pass the guard while logicalBlockNum + offset + count\npoints past the partition, which later indexes past the space bitmap\narray.\n\nA single ftruncate(2) on a file backed by such an extent reliably\npanics the kernel.  This is a local availability issue.  On desktop\nsystems where UDisks/polkit allows the active user to mount removable\nUDF media without CAP_SYS_ADMIN, an unprivileged local user can supply\nthe crafted filesystem and trigger the panic by truncating a writable\nfile on it.  Systems that require root or CAP_SYS_ADMIN to mount the\nimage have a higher prerequisite.\n\nNo confidentiality or integrity impact is claimed: the reproduced\nprimitive is an out-of-bounds read of a bitmap pointer slot followed by\na kernel panic.\n\nUse the already computed logicalBlockNum + offset + count value for the\npartition length check.  Also make load_block_bitmap() reject an\nout-of-range block group before indexing s_block_bitmap[], so corrupted\ncallers cannot walk past the flexible array.",
  "id": "GHSA-mpf7-xmx2-frhw",
  "modified": "2026-07-27T06:30:33Z",
  "published": "2026-07-25T12:31:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64324"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/12af328d2ee8d68e81ba612246d0b54b22d23e1f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/335202ab25b01fdd45889ff25eab70864686dea3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9442d75429b0c556292a7454fe888d54259f5240"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b54aee5652fcd7c23a0904a4623ec462c3edc70c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/be87de7789a82a030a4896bc7683415ec9fa6f2b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fb49099206c5c57af28a157249fa7bcb5518f99e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fdd6229d2ae9914c1f25d1041db0f4f312a4fa76"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-64324 (GCVE-0-2026-64324)

GHSA-MPF7-XMX2-FRHW

Tags

Sightings

Nomenclature