How severe is CVE-2026-72343?

No CVSS score has been assigned to CVE-2026-72343 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-72343?

CVE-2026-72343 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-72343?

Update Kernel to 6.1.178 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72343 is resolved across your whole dependency graph.

How do I detect CVE-2026-72343 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-2026-72343 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-2026-72343?

O3 pinpoints whether CVE-2026-72343 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-2026-72343 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-72343 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-2026-72343 published, and has it been updated?

CVE-2026-72343 was published on August 15, 2026 and was last updated on August 16, 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

CVE-2026-72343

CVE-2026-72343 is a security vulnerability in Kernel. O3 Security confirms whether CVE-2026-72343 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

net/mlx5e: Fix HV VHCA stats zero-sized buffer allocation

Published

Aug 15, 2026

Updated

Aug 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 16, 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:

net/mlx5e: Fix HV VHCA stats zero-sized buffer allocation

mlx5e_hv_vhca_stats_create() is called from mlx5e_nic_enable(), before mlx5e_open(). At that point priv->stats_nch is still zero, because it is only ever incremented in mlx5e_channel_stats_alloc(), which is reached only from mlx5e_open_channel().

mlx5e_hv_vhca_stats_buf_size() therefore returns 0, and kvzalloc(0, GFP_KERNEL) returns ZERO_SIZE_PTR ((void *)16) rather than NULL. The "if (!buf)" guard does not catch this, and mlx5e_hv_vhca_stats_create() completes "successfully" with priv->stats_agent.buf set to ZERO_SIZE_PTR.

Once channels are opened (priv->stats_nch > 0) and the hypervisor enables stats reporting, mlx5e_hv_vhca_stats_work() recomputes buf_len using the new non-zero stats_nch and calls memset(buf, 0, buf_len) on ZERO_SIZE_PTR, faulting at address 0x10.

Allocate the buffer based on priv->max_nch, which is set in mlx5e_priv_init() and is the upper bound on stats_nch:

Add a separate helper mlx5e_hv_vhca_stats_buf_max_size() that returns sizeof(per_ring_stats) * max(max_nch, stats_nch), and use it for the kvzalloc() in mlx5e_hv_vhca_stats_create().
Keep mlx5e_hv_vhca_stats_buf_size() (which returns based on stats_nch) for the worker's active payload size, so the wire format (block->rings = stats_nch) and the amount of data filled by mlx5e_hv_vhca_fill_stats() are unchanged.

The max(max_nch, stats_nch) guard handles the rare case where mlx5e_attach_netdev() recomputes max_nch downward across a detach/resume cycle while priv->stats_nch persists (mlx5e_detach_netdev does not call mlx5e_priv_cleanup, so stats_nch is only reset when the netdev is destroyed). Without the guard, the worker could compute buf_len from stats_nch and overrun the smaller buffer allocated based on the reduced max_nch.

Allocating a non-zero buffer also makes the kvzalloc() failure path in mlx5e_hv_vhca_stats_create() reachable for the first time: it returns early without (re)creating the agent. Clear priv->stats_agent.{agent,buf} in mlx5e_hv_vhca_stats_destroy() after freeing them, so that if a later create() bails out on this path, a subsequent teardown does not double-free the stale agent/buffer left from a previous enable/disable cycle.

This mirrors the existing mlx5e pattern of preallocating arrays of size max_nch (e.g. priv->channel_stats) and lazily populating entries up to stats_nch on demand.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 5.17.0&&< 6.1.178	6.1.178

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 6.1.178 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72343 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-2026-72343 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-2026-72343. 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: net/mlx5e: Fix HV VHCA stats zero-sized buffer allocation mlx5e_hv_vhca_stats_create() is called from mlx5e_nic_enable(), before mlx5e_open(). At that point priv->stats_nch is still zero, because it is only ever incremented in mlx5e_channel_stats_alloc(), which is reached only from mlx5e_open_channel(). mlx5e_hv_vhca_stats_buf_size() therefore returns 0, and kvzalloc(0, GFP_KERNEL) returns ZERO_SIZE_PTR ((void *)16) rather than NULL. The "if (!buf)" guard does not catch this, and mlx5e_hv_vhca_stats_create() completes "succ

O3 Security · Impact-Aware SCA

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