Stale kernel-memory read via cttimeout unload race
Published Sep 25, 2026 · Updated Sep 25, 2026
A use-after-free in Linux 5.13 allows local users to trigger a stale kernel-memory read during nfnetlink_cttimeout module unload. cttimeout_exit() unregisters per-network operations before clearing nf_ct_timeout_hook, so a concurrent policy lookup dereferences freed per-network storage. Reaching the race requires privileged module teardown concurrent with an iptables timeout-policy lookup; the public record demonstrates a KASAN-detected read but does not establish code execution or data disclosure.
Summary
What happened
A use-after-free in Linux 5.13 allows local users to trigger a stale kernel-memory read during nfnetlink_cttimeout module unload. cttimeout_exit() unregisters per-network operations before clearing nf_ct_timeout_hook, so a concurrent policy lookup dereferences freed per-network storage. Reaching the race requires privileged module teardown concurrent with an iptables timeout-policy lookup; the public record demonstrates a KASAN-detected read but does not establish code execution or data disclosure.
The record
- CVE
- CVE-2026-97609
- 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.13
- Affected versionversion=ebfbe67568a734a449203097b02c4ab884257535 <1f69c570a73f2dedf75ea5166d47622d5fa958c1
- Affected versionversion=ebfbe67568a734a449203097b02c4ab884257535 <a7fdd86c386b7f7cc72a126389c2cdb55d035221
- Affected versionversion=ebfbe67568a734a449203097b02c4ab884257535 <fec9b1de0d02de8dafa3cc344bcb91cf28660643
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
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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Your stack
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