CVE-2026-90102: In the Linux kernel, the following vulnerability has been resolved: NFSv4/pnfs: key the data server cache on the NFS version nfs4_pnfs_ds

In the Linux kernel, the following vulnerability has been resolved: NFSv4/pnfs: key the data server cache on the NFS version nfs4_pnfs_ds_add() keys the per-n

In the Linux kernel, the following vulnerability has been resolved: NFSv4/pnfs: key the data server cache on the NFS version nfs4_pnfs_ds_add() keys the per-net data server cache on the multipath address set alone, and struct nfs4_pnfs_ds records no version. That suffices for the files layout driver, which always connects with version 4, but flexfiles takes its version tuple from GETDEVICEINFO per device, and one address can legitimately serve both NFSv3 and NFSv4. Two deviceids on one address with different ds_versions[0].version therefore share a single nfs4_pnfs_ds, and whichever mirror connects first pins ds_clp to its own version. The other one is handed that client anyway, so it selects rpc_call_ops for a version the connection does not speak, and the mismatched sequence-slot handling dereferences NULL. Add the version to the cache key so the two cannot alias, giving each version its own nfs4_pnfs_ds and connection while both mirrors stay usable. Only the major version is compared, since that is what selects rpc_call_ops and rpc_ops; v4.0 and v4.1 keep sharing a client. The files layout driver passes the 4 it already hardcodes at connect time.

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.70%, higher than 52% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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