# CVE-2026-80862: nvme-tcp: fix usage of page_frag_cache

> A race condition in the Linux kernel's NVMe-TCP driver causes premature page freeing, leading to system crashes or potential code execution.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2026-80862, DEBIAN-CVE-2026-80862, GHSA-r23c-4v3q-555g, UBUNTU-CVE-2026-80862

## What is CVE-2026-80862?

CVE-2026-80862 is an use after free vulnerability in Linux, published on 4 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:

nvme-tcp: fix usage of page_frag_cache

nvme uses page_frag_cache to preallocate PDU for each preallocated request
of block device. Block devices are created in parallel threads,
consequently page_frag_cache is used in not thread-safe manner.
That leads to incorrect refcounting of backstore pages and premature free.

That can be catched by !sendpage_ok inside network stack:

WARNING: CPU: 7 PID: 467 at ../net/core/skbuff.c:6931 skb_splice_from_iter+0xfa/0x310.
	tcp_sendmsg_locked+0x782/0xce0
	tcp_sendmsg+0x27/0x40
	sock_sendmsg+0x8b/0xa0
	nvme_tcp_try_send_cmd_pdu+0x149/0x2a0
Then random panic may occur.

Fix that by serializing the usage of page_frag_cache.

## Which versions are affected by CVE-2026-80862?


## How do I fix CVE-2026-80862?

Apply the vendor's patch.

## Is CVE-2026-80862 being exploited?

There is no known exploitation of CVE-2026-80862 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80862 and fix it if it is affected.

What it is: CVE-2026-80862 is an use after free vulnerability in Linux, published on 4 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-2026-80862 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-2026-80862/ (Markdown: https://insights.sbomify.com/CVE-2026-80862/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80862
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80862
- OSV: https://osv.dev/vulnerability/CVE-2026-80862

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80862/
Summaries are generated and may contain mistakes; the official description above is the record.