CVE-2026-89694

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: check client ownership when cancelling a copy-notify stateid On the OFFLOAD_CANCEL path (clp != NULL), manage_cpntf_state() freed the target cpntf state without checking ownership. The lookup key st->si_opaque.so_id is allocated cyclically (guessable) and the embedded clientid is the fixed per-net nn->s2s_cp_cl_id, so any authenticated NFSv4.2 client could cancel and free another client's copy-notify stateid. Compare the creating clientid recorded in state->cp_p_clid against the requesting client's cl_clientid and return nfserr_bad_stateid on a mismatch instead of freeing the entry.

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EPSS — Exploit Prediction

0.0021

Probability of exploitation

0.11%

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/6bba72b8ee68ad631b94bd439592cba46de54d7d https://git.kernel.org/stable/c/6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf https://git.kernel.org/stable/c/75268f6cfe26b09a7e4d3216367e87fe9e2a26aa https://git.kernel.org/stable/c/81b2cfe767943922eca906a2a5af23a0ce5d0f35 https://git.kernel.org/stable/c/88daaed26e17e1c7e851859b5bbb4f0e1ab6d0e9 https://git.kernel.org/stable/c/b1eca07303594ca27f5dc360a6946bd7e1f5b04c https://git.kernel.org/stable/c/b42dc26a14b4ad5d6daaada11ec4c70744141c25 https://git.kernel.org/stable/c/d801906165cb5cc250d5cbe44935594e170be3e2

Frequently Asked Questions

What is CVE-2026-89694? +

In the Linux kernel, the following vulnerability has been resolved: nfsd: check client ownership when cancelling a copy-notify stateid On the OFFLOAD_CANCEL path (clp != NULL), manage_cpntf_state() freed the target cpntf state without checking ownership. The lookup key st->si_opaque.so_id is allocated cyclically (guessable) and the embedded clientid is the fixed per-net nn->s2s_cp_cl_id, so any authenticated NFSv4.2 client could cancel and free another client's copy-notify stateid. Compare the creating clientid recorded in state->cp_p_clid against the requesting client's cl_clientid and return nfserr_bad_stateid on a mismatch instead of freeing the entry.

How do I check if I'm vulnerable to CVE-2026-89694? +

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.