Local memory corruption via CT teardown race
Published Sep 11, 2026 · Updated Sep 11, 2026
Use-after-free in Linux kernel Open vSwitch allows local users to corrupt kernel memory during network-namespace teardown. Packet processing dereferences CT-limit state after teardown frees it without first removing the pointer from RCU readers or waiting for a grace period. An unprivileged user must create user and network namespaces and race packet processing with namespace teardown; the established consequence is a slab use-after-free in ovs_ct_execute().
Summary
What happened
Use-after-free in Linux kernel Open vSwitch allows local users to corrupt kernel memory during network-namespace teardown. Packet processing dereferences CT-limit state after teardown frees it without first removing the pointer from RCU readers or waiting for a grace period. An unprivileged user must create user and network namespaces and race packet processing with namespace teardown; the established consequence is a slab use-after-free in ovs_ct_execute().
The record
- CVE
- CVE-2026-89488
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 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=11efd5cb04a184eea4f57b68ea63dddd463158d1 <403f96c32c9e24600093d7d0c61c17daeedca957
- Affected versionversion=11efd5cb04a184eea4f57b68ea63dddd463158d1 <6a6d36fadb8537d9b79e72c9fa51885ec0c33e10
- Affected versionversion=11efd5cb04a184eea4f57b68ea63dddd463158d1 <e15407c3a8a005324f633cd46cd8fb58042c1157
- Affected versionversion=4.18
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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