Sceawere
Vulnerability Detail
CVE-2026-74356 Verified Sceawere Triage Sources: NVD / CISA KEV
Vulnerability Metadata
- Severity
- High
- Score / CVSS
- 7.4
- Creation Date
- 2d ago
- Vendor
- Linux
- Product
- Linux
- Attack Type
- N/A
- Vector String
- CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Attack Complexity
- LOW
Narrative and Response
Description
In the Linux kernel, the following vulnerability has been resolved: vhost: fix vhost_get_avail_idx for a non empty ring vhost_get_avail_idx is supposed to report whether it has updated vq->avail_idx. Instead, it returns whether all entries have been consumed, which is usually the same. But not always - in drivers/vhost/net.c and when mergeable buffers have been enabled, the driver checks whether the combined entries are big enough to store an incoming packet. If not, the driver re-enables notifications with available entries still in the ring. The incorrect return value from vhost_get_avail_idx propagates through vhost_enable_notify and causes the host to livelock if the guest is not making progress, as vhost will immediately disable notifications and retry using the available entries. This goes back to commit d3bb267bbdcb ("vhost: cache avail index in vhost_enable_notify()") which changed vhost_enable_notify() to compare the freshly read avail index against vq->last_avail_idx instead of the previously cached vq->avail_idx. Commit 7ad472397667 ("vhost: move smp_rmb() into vhost_get_avail_idx()") then carried over the same comparison when refactoring vhost_enable_notify() to call the unified vhost_get_avail_idx(). The obvious fix is to make vhost_get_avail_idx do what the comment says it does and report whether new entries have been added.
Executive Summary
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Technical Details
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Mitigations
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
References
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
Additional Metadata
{
"score": "7.4",
"pubDate": "2026-08-15T06:22:37.007Z",
"pubdate": "2026-08-15T06:22:37.007Z"
}