# CVE-2026-23242: RDMA/siw: Fix potential NULL pointer dereference in header processing

> A NULL pointer dereference in the Linux kernel's RDMA/siw module allows attackers to cause a system crash via crafted network packets.

- **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:** 18 Mar 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-79980, BELL-CVE-2026-23242, DEBIAN-CVE-2026-23242, GHSA-6xq4-2j3g-9m44, ROOT-OS-DEBIAN-11-CVE-2026-23242, ROOT-OS-DEBIAN-12-CVE-2026-23242, ROOT-OS-DEBIAN-13-CVE-2026-23242, ROOT-OS-UBUNTU-2204-CVE-2026-23242, ROOT-OS-UBUNTU-2404-CVE-2026-23242, UBUNTU-CVE-2026-23242

## What is CVE-2026-23242?

CVE-2026-23242 is a high-severity vulnerability in Linux kernel, published on 18 Mar 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: Fix potential NULL pointer dereference in header processing

If siw_get_hdr() returns -EINVAL before set_rx_fpdu_context(),
qp->rx_fpdu can be NULL. The error path in siw_tcp_rx_data()
dereferences qp->rx_fpdu->more_ddp_segs without checking, which
may lead to a NULL pointer deref. Only check more_ddp_segs when
rx_fpdu is present.

KASAN splat:
[  101.384271] KASAN: null-ptr-deref in range [0x00000000000000c0-0x00000000000000c7]
[  101.385869] RIP: 0010:siw_tcp_rx_data+0x13ad/0x1e50

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-23242?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23242?

Apply the vendor's patch.

## Is CVE-2026-23242 being exploited?

There is no known exploitation of CVE-2026-23242 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23242 and fix it if it is affected.

What it is: CVE-2026-23242 is a high-severity vulnerability in Linux kernel, published on 18 Mar 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-2026-23242 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-23242/ (Markdown: https://insights.sbomify.com/CVE-2026-23242/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23242
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23242
- OSV: https://osv.dev/vulnerability/CVE-2026-23242

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23242/
Summaries are generated and may contain mistakes; the official description above is the record.