Kernel memory read via unchecked ext4 index pointer
Published Apr 22, 2026 · Updated Apr 22, 2026
Out-of-bounds read in ext4 in affected Linux Kernel releases allows local users to read kernel memory via a crafted filesystem image. The ext4_ext_correct_indexes() function dereferences path[k].p_idx->ei_block without checking p_idx against EXT_LAST_INDEX(), so crafted eh_entries metadata moves the pointer past the slab buffer. Exploitation requires user interaction to introduce and use the image; the resulting read can disclose adjacent kernel data or interrupt the system.
Summary
What happened
Out-of-bounds read in ext4 in affected Linux Kernel releases allows local users to read kernel memory via a crafted filesystem image. The ext4_ext_correct_indexes() function dereferences path[k].p_idx->ei_block without checking p_idx against EXT_LAST_INDEX(), so crafted eh_entries metadata moves the pointer past the slab buffer. Exploitation requires user interaction to introduce and use the image; the resulting read can disclose adjacent kernel data or interrupt the system.
The record
- CVE
- CVE-2026-31449
- Published
- Apr 22, 2026
- Updated
- Apr 22, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 22, 2026CVE publishedPublication date reported by the CVE source.
- Apr 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <01bf1e0b997d82c0e353b51ed74ef99698043c33
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <407c944f217c17d4343148011acafebc604d55e1
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <93f2e975ed658ce09db4d4c2877ca2c06540df83
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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