# CVE-2026-98323: RDMA/siw: Bound fragmented header copies by the remaining length

> A buffer overflow in the Linux kernel RDMA driver allows attackers to overwrite memory and potentially execute code or escalate privileges.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106458, BELL-CVE-2026-98323, DEBIAN-CVE-2026-98323, GHSA-6mmc-6x3m-rgjh, UBUNTU-CVE-2026-98323

## What is CVE-2026-98323?

CVE-2026-98323 is a critical memory corruption vulnerability in Linux, published on 6 Oct 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:

RDMA/siw: Bound fragmented header copies by the remaining length

siw_get_hdr() can receive an extended DDP/RDMAP header across more than
one TCP callback. The first callback may receive most of the header,
while the next one still limits the copy to hdrlen - MIN_DDP_HDR instead
of the number of missing bytes. This makes the destination move past the
end of the header and overwrite the receive state, including
fpdu_part_rcvd. A later callback can then use a negative fpdu_part_rcvd
value as a copy offset, which creates an OOB write.

Use the number of header bytes already received when calculating the
next copy length.

## Which versions are affected by CVE-2026-98323?


## How do I fix CVE-2026-98323?

Apply the vendor's patch.

## Is CVE-2026-98323 being exploited?

There is no known exploitation of CVE-2026-98323 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98323 and fix it if it is affected.

What it is: CVE-2026-98323 is a critical memory corruption vulnerability in Linux, published on 6 Oct 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-2026-98323 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-2026-98323/ (Markdown: https://insights.sbomify.com/CVE-2026-98323/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98323
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98323
- OSV: https://osv.dev/vulnerability/CVE-2026-98323

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98323/
Summaries are generated and may contain mistakes; the official description above is the record.