CVE-2026-80858

Description

In the Linux kernel, the following vulnerability has been resolved: fuse: publish io-uring queues with release semantics fuse_uring_create_queue() initializes a fuse_ring_queue and then publishes the pointer into ring->queues[qid] with WRITE_ONCE() under the fch->lock. There are several readers that may concurrently be fetching that pointer locklessly and then deferencing it. WRITE_ONCE() doesn't ensure ordering of the queue's field initialization before the ring->queues[qid] pointer assignment. The queue must be published with smp_store_release() so the field initialization is guaranteed to happen before. Readers in paths where the read may happen concurrently with the store need to use READ_ONCE() because any race involving a plain access is undefined.

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EPSS — Exploit Prediction

0.0016

Probability of exploitation

0.05%

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/42df916e5a5f8fb4b60c8cefb54318d1ec02c580 https://git.kernel.org/stable/c/a1bb359c443d048fe5dfd6ca9caf4e3897f3e9aa

Frequently Asked Questions

What is CVE-2026-80858? +

In the Linux kernel, the following vulnerability has been resolved: fuse: publish io-uring queues with release semantics fuse_uring_create_queue() initializes a fuse_ring_queue and then publishes the pointer into ring->queues[qid] with WRITE_ONCE() under the fch->lock. There are several readers that may concurrently be fetching that pointer locklessly and then deferencing it. WRITE_ONCE() doesn't ensure ordering of the queue's field initialization before the ring->queues[qid] pointer assignment. The queue must be published with smp_store_release() so the field initialization is guaranteed to happen before. Readers in paths where the read may happen concurrently with the store need to use READ_ONCE() because any race involving a plain access is undefined.

How do I check if I'm vulnerable to CVE-2026-80858? +

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.