CVE-2026-64291
iommufd: Set veventq_depth upper bound
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).
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Apply the patch for the Linux kernel iommufd module.
- Update the kernel to a fixed version.
- Configure veventq_depth to a safe maximum value.
- Monitor kernel memory usage.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64291.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64291 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64291
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64291 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64291 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': 'f565297edf316016be4a1a9e2eb9f39359313f43', 'versionType': 'git'}, {'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': 'e7b5e55652746b1221b9c10ff80eae8a154101ba', 'versionType': 'git'}, {'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': '6ebf2eb46fbd5b40393ff8fbb847ba96925beaff', 'versionType': 'git'}], 'programFiles': ['drivers/iommu/iommufd/eventq.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/iommu/iommufd/eventq.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': 'f565297edf316016be4a1a9e2eb9f39359313f43', 'versionType': 'git'}, {'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': 'e7b5e55652746b1221b9c10ff80eae8a154101ba', 'versionType': 'git'}, {'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': '6ebf2eb46fbd5b40393ff8fbb847ba96925beaff', 'versionType': 'git'}], 'programFiles': ['drivers/iommu/iommufd/eventq.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/iommu/iommufd/eventq.c'], 'defaultStatus': 'affected'}] -
Initial Analysis by [email protected]
Aug. 12, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.1.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.15 up to (excluding) 6.18.39 Added Reference Type kernel.org: https://git.kernel.org/stable/c/6ebf2eb46fbd5b40393ff8fbb847ba96925beaff Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/e7b5e55652746b1221b9c10ff80eae8a154101ba Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/f565297edf316016be4a1a9e2eb9f39359313f43 Types: Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': 'f565297edf316016be4a1a9e2eb9f39359313f43', 'versionType': 'git'}, {'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': 'e7b5e55652746b1221b9c10ff80eae8a154101ba', 'versionType': 'git'}, {'status': 'affected', 'version': 'e36ba5ab808ef6237c3148d469c8238674230e2b', 'lessThan': '6ebf2eb46fbd5b40393ff8fbb847ba96925beaff', 'versionType': 'git'}], 'programFiles': ['drivers/iommu/iommufd/eventq.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/iommu/iommufd/eventq.c'], 'defaultStatus': 'affected'}] Added 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). Added Reference https://git.kernel.org/stable/c/6ebf2eb46fbd5b40393ff8fbb847ba96925beaff Added Reference https://git.kernel.org/stable/c/e7b5e55652746b1221b9c10ff80eae8a154101ba Added Reference https://git.kernel.org/stable/c/f565297edf316016be4a1a9e2eb9f39359313f43