CVE-2026-64291
Published Jul 25, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: iommufd: Set veventq_depth upper bound iommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with an upper bound at U32_MAX. This leaves a vulnerability where userspace can allocate excessively large queues to exhaust kernel memory reserves. Cap the veventq_depth (maximum number of entries) to 1 << 19, matching the maximum number of entries in the SMMUv3 EVTQ (the largest use case today).
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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
Frequently Asked Questions
What is CVE-2026-64291? +
In the Linux kernel, the following vulnerability has been resolved:
iommufd: Set veventq_depth upper bound
iommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with
an upper bound at U32_MAX.
This leaves a vulnerability where userspace can allocate excessively large
queues to exhaust kernel memory reserves.
Cap the veventq_depth (maximum number of entries) to 1 << 19, matching the
maximum number of entries in the SMMUv3 EVTQ (the largest use case today).
How do I check if I'm vulnerable to CVE-2026-64291? +
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.