How severe is CVE-2026-74356?

CVE-2026-74356 has a CVSS score of 7.4/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-74356?

CVE-2026-74356 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-74356?

Update Kernel to 6.12.97 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-74356 is resolved across your whole dependency graph.

How do I detect CVE-2026-74356 in my Linux dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-74356 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-74356?

O3 pinpoints whether CVE-2026-74356 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-74356 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-74356 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-74356 published, and has it been updated?

CVE-2026-74356 was published on August 15, 2026 and was last updated on August 18, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐧

🐧 Linux

Not in CISA KEV

HIGH severity

CVE-2026-74356

HIGH

CVE-2026-74356 is a high-severity (CVSS 7.4) vulnerability in Kernel. O3 Security confirms whether CVE-2026-74356 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

vhost: fix vhost_get_avail_idx for a non empty ring

Published

Aug 15, 2026

Updated

Aug 18, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐧Kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 5.18.0&&< 6.12.97	6.12.97

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 6.12.97 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-74356 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-74356 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-74356. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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_

O3 Security · Impact-Aware SCA

Is CVE-2026-74356 in your dependencies?

O3 detects CVE-2026-74356 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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