Out-of-bounds access via unchecked AFS metadata
Published Sep 16, 2026 · Updated Sep 16, 2026
Improper input validation in the Linux kernel AFS v2 parser allows attackers to trigger out-of-bounds memory access via crafted flash metadata. The afs_parse_v2_partition function subtracts footer[8] from erase-block bounds and walks region_count entries in a fixed imginfo array without validating either flash-controlled value. Reachability requires an MTD device containing attacker-controlled AFS v2 image data to be parsed; the public patch does not state a further impact.
Summary
What happened
Improper input validation in the Linux kernel AFS v2 parser allows attackers to trigger out-of-bounds memory access via crafted flash metadata. The afs_parse_v2_partition function subtracts footer[8] from erase-block bounds and walks region_count entries in a fixed imginfo array without validating either flash-controlled value. Reachability requires an MTD device containing attacker-controlled AFS v2 image data to be parsed; the public patch does not state a further impact.
The record
- CVE
- CVE-2026-89954
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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?
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- Affected versionversion=5.2
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <18916f475057cbd2fb8ea6ae86e6b85884ad1d53
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <1bec05a68414cf8d0cab6cb42445b8603f32ffc4
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <1edea8900ca3e405c1421d8b5c29f97107874f72
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <3ad8ff12fd44b08af9212ac4883a7e29d2ab7348
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <875daa3c750814ff2e2dc050239c390048f0bcd0
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <d14e6298139f58a87a87d7022e26a7f37f0ddce7
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <da740539e8f370767317e24615349b9342a6e773
- Affected versionversion=b7cf5e2830bbb128699d7635ce8404b7f605bc95 <e9290031f736e99ad17c25c00311c92c266843b7
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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