Description
In the Linux kernel, the following vulnerability has been resolved:

NTB: ntb_netdev: Preserve RX queue depth on allocation failure

ntb_netdev_rx_handler() hands the received skb to the network stack
before allocating its replacement. If the allocation fails, nothing is
reposted. Every failure therefore takes one buffer out of the RX queue
while the interface remains up, and enough failures eventually stall
reception.

A retry path could refill the queue later, but ntb_netdev has none.
Allocate the replacement first instead. If that fails, drop the packet
and repost the same skb. This keeps the queue full and lets packet
delivery resume as soon as memory is available again.
Published: 2026-08-22
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service via RX queue depletion
Action: Apply Patch
AI Analysis

Impact

The ntb_netdev driver in the Linux kernel forwards received packets to the network stack before allocating a replacement socket buffer. If the allocation fails, the packet is lost and the driver does not repost a buffer. Every such failure removes one buffer from the receive queue, and repeated failures gradually drain the queue until the NIC can no longer accept traffic, effectively stopping the interface and causing a denial‑of‑service attack. The weakness is a resource management flaw, identified as CWE‑826.

Affected Systems

All Linux kernel installations that load the ntb_netdev module for near‑field interface bridges are potentially affected. The problem exists in any kernel version prior to the recent patch and therefore applies to servers routers, storage controllers, or virtual hosts configured with the NTB interface. The scope covers any system where the ntb_netdev driver has been loaded, not just the kernel itself, because the failure condition is specific to the driver implementation.

Risk and Exploitability

The CVSS score of 7.5 classifies the issue as high severity. The EPSS score of less than 1% indicates that the vulnerability is currently considered unlikely to be exploited, and it is not listed in the CISA KEV catalog. However, because the flaw is triggered by repeated allocation failures, an attacker could potentially bring it out of a low‑probability state by generating sustained traffic or applying memory pressure to a vulnerable system, thereby draining the receive queue and disabling the interface. The lack of an official workaround means the risk remains until a kernel update is applied.

Generated by OpenCVE AI on August 25, 2026 at 16:13 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade the kernel to a version that contains the ntb_netdev patch that preserves the RX queue depth.
  • Deploy any distribution‑specific kernel updates that reference the updated ntb_netdev driver.
  • If a patched kernel is not immediately available, implement traffic shaping or rate limits on interfaces that use the NTB driver to reduce the likelihood of allocation failures and queue depletion.

Generated by OpenCVE AI on August 25, 2026 at 16:13 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4777-1 linux security update
Debian DSA Debian DSA DSA-6477-1 linux security update
History

Thu, 27 Aug 2026 13:00:00 +0000


Tue, 25 Aug 2026 14:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-400

Tue, 25 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-826
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 25 Aug 2026 09:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-400

Tue, 25 Aug 2026 07:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-400

Tue, 25 Aug 2026 05:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Sun, 23 Aug 2026 13:15:00 +0000


Sat, 22 Aug 2026 17:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-400

Sat, 22 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: NTB: ntb_netdev: Preserve RX queue depth on allocation failure ntb_netdev_rx_handler() hands the received skb to the network stack before allocating its replacement. If the allocation fails, nothing is reposted. Every failure therefore takes one buffer out of the RX queue while the interface remains up, and enough failures eventually stall reception. A retry path could refill the queue later, but ntb_netdev has none. Allocate the replacement first instead. If that fails, drop the packet and repost the same skb. This keeps the queue full and lets packet delivery resume as soon as memory is available again.
Title NTB: ntb_netdev: Preserve RX queue depth on allocation failure
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-27T12:39:48.605Z

Reserved: 2026-08-15T05:44:03.921Z

Link: CVE-2026-74626

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-22T16:16:35.517

Modified: 2026-08-27T13:18:34.740

Link: CVE-2026-74626

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-22T00:00:00Z

Links: CVE-2026-74626 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-25T16:15:05Z

Weaknesses
  • CWE-826

    Premature Release of Resource During Expected Lifetime