CVE-2026-90102 (CVSS 7.5)

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0070

Probability of exploitation

0.52%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

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

Frequently Asked Questions

What is 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_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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-90102? +

CVE-2026-90102 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0070, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-90102? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-90102