# CVE-2026-80987: NTB: ntb_transport: Reject oversized TX buffers

> An attacker can cause a memory leak in the Linux kernel NTB transport driver by sending oversized TX buffers, leading to resource exhaustion.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-100880, BELL-CVE-2026-80987, DEBIAN-CVE-2026-80987, GHSA-485c-xrj6-wvh4, UBUNTU-CVE-2026-80987

## What is CVE-2026-80987?

CVE-2026-80987 is a high-severity denial of service vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

## Which versions are affected by CVE-2026-80987?


## How do I fix CVE-2026-80987?

Apply the vendor's patch.

## Is CVE-2026-80987 being exploited?

There is no known exploitation of CVE-2026-80987 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80987 and fix it if it is affected.

What it is: CVE-2026-80987 is a high-severity denial of service vulnerability in Linux, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80987 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80987/ (Markdown: https://insights.sbomify.com/CVE-2026-80987/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80987
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80987
- OSV: https://osv.dev/vulnerability/CVE-2026-80987

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80987/
Summaries are generated and may contain mistakes; the official description above is the record.