Answer in brief
CVE-2026-89658 records a Critical severity (CVSS 9.8) vulnerability in NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=d688d8585e6bea5e4e37f7497feea93b6b0a469c <0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519 || >=d688d8585e6bea5e4e37f7497feea93b6b0a469c <b413ec5b23e3445dc9c4f273116078e2d4747626 || >=d688d8585e6bea5e4e37f7497feea93b6b0a469c <81cf7f1413862f87b078920c838460a6a88aa030 || >=d688d8585e6bea5e4e37f7497feea93b6b0a469c <7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55 | 0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519, b413ec5b23e3445dc9c4f273116078e2d4747626, 81cf7f1413862f87b078920c838460a6a88aa030, 7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55 |
| Linux/Linuxgeneric | 6.9 | Not reported |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup nfs40_clean_admin_revoked() takes a stateid reference under clp->cl_lock, drops nn->client_lock, and calls nfsd4_drop_revoked_stid(), which dereferences the stateid's client through s->sc_client->cl_lock. The stateid reference does not pin the client, so a teardown racing the dropped lock can free the client while nfsd4_drop_revoked_stid() is still using it. This cleanup runs from the laundromat, so a periodic sweep can race force_expire_client() driven by a write to the clients/<id>/ctl file. Skip a client that is already expiring and otherwise pin it with cl_rpc_users under client_lock before dropping the lock, matching nfsd4_revoke_states().
Quoted source text, attributed separately from HOL analysis.