# CVE-2026-3038: Local DoS and possible privilege escalation via routing sockets

> An unprivileged user can crash the FreeBSD kernel via a stack buffer overflow in routing sockets, potentially leading to privilege escalation if mitigations are bypassed.

- **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:** No
- **Published:** 9 Mar 2026
- **Updated:** 9 Mar 2026
- **Also known as:** GHSA-jjxv-p5qr-w2hv

## What is CVE-2026-3038?

CVE-2026-3038 is a high-severity memory corruption vulnerability in Freebsd Freebsd, published on 9 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The rtsock_msg_buffer() function serializes routing information into a buffer.  As a part of this, it copies sockaddr structures into a sockaddr_storage structure on the stack.  It assumes that the source sockaddr length field had already been validated, but this is not necessarily the case, and it's possible for a malicious userspace program to craft a request which triggers a 127-byte overflow.

 In practice, this overflow immediately overwrites the canary for the rtsock_msg_buffer() stack frame, resulting in a panic once the function returns.

The bug allows an unprivileged user to crash the kernel by triggering a stack buffer overflow in rtsock_msg_buffer().  In particular, the overflow will corrupt a stack canary value that is verified when the function returns; this mitigates the impact of the stack overflow by triggering a kernel panic.

Other kernel bugs may exist which allow userspace to find the canary value and thus defeat the mitigation, at which point local privilege escalation may be possible.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-3038?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2026-3038?

No fix has been published for CVE-2026-3038 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3038 being exploited?

There is no known exploitation of CVE-2026-3038 in the wild and no public exploit code.

## Other vulnerabilities in Freebsd Freebsd

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3038 and fix it if it is affected.

What it is: CVE-2026-3038 is a high-severity memory corruption vulnerability in Freebsd Freebsd, published on 9 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-2026-3038 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. 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-2026-3038/ (Markdown: https://insights.sbomify.com/CVE-2026-3038/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3038
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3038
- OSV: https://osv.dev/vulnerability/CVE-2026-3038

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3038/
Summaries are generated and may contain mistakes; the official description above is the record.