Application crash via zero-entry extent header
Published Jun 3, 2026 · Updated Jun 3, 2026
Out-of-bounds read in lwext4 1.0.0 allows attackers to crash a consuming application with a crafted ext4 filesystem image. In ext4_ext_binsearch_idx, an internal-node header with eh_entries set to zero causes EXT_FIRST_INDEX and EXT_LAST_INDEX to produce invalid binary-search pointers. The application must process the image, and the demonstrated consequence is a segmentation fault during extent-tree traversal.
Summary
What happened
Out-of-bounds read in lwext4 1.0.0 allows attackers to crash a consuming application with a crafted ext4 filesystem image. In ext4_ext_binsearch_idx, an internal-node header with eh_entries set to zero causes EXT_FIRST_INDEX and EXT_LAST_INDEX to produce invalid binary-search pointers. The application must process the image, and the demonstrated consequence is a segmentation fault during extent-tree traversal.
The record
- CVE
- CVE-2025-70101
- Published
- Jun 3, 2026
- Updated
- Jun 3, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-125, CAPEC-540, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 3, 2026CVE publishedPublication date reported by the CVE source.
- Jun 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- Malformed ext4 extent-header crash proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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