Kernel use-after-free via undrained teardown work
Published Sep 16, 2026 · Updated Sep 16, 2026
Use-after-free in the Linux cx23885 NetUP CI teardown path allows attackers to trigger freed-memory access during device removal. netup_ci_exit() frees netup_ci_state without draining a queued netup_read_ci_status() work item, which later derives and dereferences the stale state pointer. The path requires a NetUP Dual DVB-S2 CI card and device teardown; consequences beyond the freed-memory dereference are not published.
Summary
What happened
Use-after-free in the Linux cx23885 NetUP CI teardown path allows attackers to trigger freed-memory access during device removal. netup_ci_exit() frees netup_ci_state without draining a queued netup_read_ci_status() work item, which later derives and dereferences the stale state pointer. The path requires a NetUP Dual DVB-S2 CI card and device teardown; consequences beyond the freed-memory dereference are not published.
The record
- CVE
- CVE-2026-89893
- 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=2.6.30
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <140ecbcbf978fbe60f83f8d4f8b1199029a5c763
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <4e143d662ca94888b494b2427fc9e34494eb933a
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <5deec890ecfa04d21cfa9bb9a2fe5e9dc98db5c5
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <99cd62b9b1c818d6d01a87be9a8e5796314150a2
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <aaf76794b870b0f391eff339252a2e2e22f33a4a
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <bf3f49273d5bf6acbdad18ff44c01ffcf7a7a146
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <ec82b0cf7f75fd95802592dcc9560fc7f529bba4
- Affected versionversion=c184dcd282337c09695a4c1761d7ac77fdc8fb7d <f7ff5adb63c1b277565afa54ccc0924d841b4a52
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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