CVSS v3
9.8
CRITICAL
EPSS Score
0.7 %
exploit probability, as of 2026-09-28
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown After a DESTROY_SESSION the per-session teardown path can free a session while rpciod still holds an inflight callback rpc_task that dereferences clp->cl_cb_session. nfsd4_probe_callback_sync() flushes cl_callback_wq, but once nfsd4_run_cb_work() has called rpc_call_async() the rpc_task lives on rpciod; flushing the workqueue does not wait for it. rpc_
Technical details
- Published
- 2026-09-11
- Last Modified
- 2026-09-13
Frequently asked questions
What is CVE-2026-89708?
In the Linux kernel, the following vulnerability has been resolved: nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown After a DESTROY_SESSION the per-session teardown path can free a session while rpciod still holds an inflight callback rpc_task that dereferences clp->cl_cb_session. nfsd4_probe_callback_sync() flushes cl_callback_wq, but once nfsd4_run_cb_work() has called rpc_call_async() the rpc_task lives on rpciod; flushing the workqueue does not wait for it. rpc_
Is CVE-2026-89708 actively exploited?
Active exploitation of CVE-2026-89708 has not been confirmed. Its EPSS score was 0.7% on 2026-09-28, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2026-89708?
CVE-2026-89708 has a CVSS v3 base score of 9.8 (CRITICAL severity).
Is CVE-2026-89708 affecting your environment?
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