Use-after-free via recycled BPF map timer
Published Sep 25, 2026 · Updated Sep 25, 2026
Use-after-free in Linux 7.2 allows local users able to load BPF programs to trigger a freed-memory timer callback through a resizable hash map. rhtab_map_update_elem() reinitializes a recycled element and clears the only timer pointer before its deferred destructor can cancel the timer. Exploitation requires permission to load the necessary BPF program; the documented result is a callback whose key and value reference freed memory.
Summary
What happened
Use-after-free in Linux 7.2 allows local users able to load BPF programs to trigger a freed-memory timer callback through a resizable hash map. rhtab_map_update_elem() reinitializes a recycled element and clears the only timer pointer before its deferred destructor can cancel the timer. Exploitation requires permission to load the necessary BPF program; the documented result is a callback whose key and value reference freed memory.
The record
- CVE
- CVE-2026-98036
- Published
- Sep 25, 2026
- Updated
- Sep 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 25, 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=6905f8601298ecd2d1932a4b4849bf265201118e <5df46ddcb7b36878c1b691e9057a0509042a2567
- Affected versionversion=6905f8601298ecd2d1932a4b4849bf265201118e <6a5266b8288216b86602ff687d528abfb066dfd8
- Affected versionversion=7.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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