Answer in brief
CVE-2026-90039 records a Unknown severity vulnerability in NFSD: Guard admin state-revocation walks with NFSD_NET_UP. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), 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.
A CVSS score is not reported in the current record. 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), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 6.9 | Not reported |
| Linux/Linuxgeneric | >=1ac3629bf012592cb0320e52a1cceb319a05ad17 <73bf459d696ecf207a9037bf9bb70c51a459469e || >=1ac3629bf012592cb0320e52a1cceb319a05ad17 <104a51265042b4424085741c963cb858ac29ec0b || >=1ac3629bf012592cb0320e52a1cceb319a05ad17 <0146467a2fce845cb6629979c3e9c58dd3d3a6a3 || >=1ac3629bf012592cb0320e52a1cceb319a05ad17 <2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378 | 73bf459d696ecf207a9037bf9bb70c51a459469e, 104a51265042b4424085741c963cb858ac29ec0b, 0146467a2fce845cb6629979c3e9c58dd3d3a6a3, 2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378 |
| Linux/Linuxgeneric | >=1ac3629bf012592cb0320e52a1cceb319a05ad17 <104a51265042b4424085741c963cb858ac29ec0b || >=1ac3629bf012592cb0320e52a1cceb319a05ad17 <0146467a2fce845cb6629979c3e9c58dd3d3a6a3 || >=1ac3629bf012592cb0320e52a1cceb319a05ad17 <2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378 | 104a51265042b4424085741c963cb858ac29ec0b, 0146467a2fce845cb6629979c3e9c58dd3d3a6a3, 2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378 |
Published upstream
Sep 16, 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 16, 2026
In the Linux kernel, the following vulnerability has been resolved: NFSD: Guard admin state-revocation walks with NFSD_NET_UP Writing to /proc/fs/nfsd/unlock_filesystem, or sending the NFSD_CMD_UNLOCK_FILESYSTEM or NFSD_CMD_UNLOCK_EXPORT netlink command, walks the NFSv4 client hash tables to revoke open state and cancel async COPY operations. All three handlers gate that walk on nn->nfsd_serv, but a listener added via portlist or netlink listener_set sets nn->nfsd_serv before any nfsd thread starts. nfsd_startup_net() has not yet allocated nn->conf_id_hashtbl, so the walkers dereference a NULL table. A local administrator with CAP_SYS_ADMIN can crash the kernel this way without ever starting the server. nn->nfsd_serv is set when the service is created, which precedes table allocation. NFSD_NET_UP instead brackets the window where the tables are live: set at the end of nfsd_startup_net() and cleared in nfsd_shutdown_net() after they are freed, both under nfsd_mutex. Gating the three unlock paths on NFSD_NET_UP fixes the startup-time NULL dereference while preserving the earlier post-shutdown use-after-free fix.
Quoted source text, attributed separately from HOL analysis.