Service interruption via teardown-time NULL pointer dereference
Published Sep 24, 2026 · Updated Sep 24, 2026
NULL pointer dereference in Linux 6.9 allows attackers to interrupt an NFS server during per-network-namespace teardown. During teardown, nfsd_file_net_dispose calls svc_wake_up on nn->nfsd_serv after that pointer is cleared when more than eight disposal entries remain queued. The condition requires an active nfsd teardown with the oversized disposal queue, and the documented consequence is limited to service availability.
Summary
What happened
NULL pointer dereference in Linux 6.9 allows attackers to interrupt an NFS server during per-network-namespace teardown. During teardown, nfsd_file_net_dispose calls svc_wake_up on nn->nfsd_serv after that pointer is cleared when more than eight disposal entries remain queued. The condition requires an active nfsd teardown with the oversized disposal queue, and the documented consequence is limited to service availability.
The record
- CVE
- CVE-2026-93212
- Published
- Sep 24, 2026
- Updated
- Sep 24, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 24, 2026CVE publishedPublication date reported by the CVE source.
- Sep 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.9
- Affected versionversion=ffb402596147ac583f3464ff5c48feb9423e3838 <59baf45a06435194005fc5fa9a42d89f77a30432
- Affected versionversion=ffb402596147ac583f3464ff5c48feb9423e3838 <766170b4fd2daaf5c4d6735560101474e18edab6
- Affected versionversion=ffb402596147ac583f3464ff5c48feb9423e3838 <9f1ddfc8cb9076592401a611eb3a44d36186d014
- Affected versionversion=ffb402596147ac583f3464ff5c48feb9423e3838 <f4776c1c4b38fbc459420321c8ece87d0f7f95fb
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
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
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Get started to see how Hinoki identifies affected software and validates exploitability in your environment.
Get started