# CVE-2026-46266: inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP

> A malicious ICMP packet can corrupt the FNHE cache via IPPROTO_RAW sockets, causing a denial of service in the Linux kernel.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:** 3 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-46266, DEBIAN-CVE-2026-46266, GHSA-3vgg-pc24-vv5m, ROOT-OS-DEBIAN-11-CVE-2026-46266, ROOT-OS-DEBIAN-12-CVE-2026-46266, ROOT-OS-UBUNTU-2204-CVE-2026-46266, ROOT-OS-UBUNTU-2404-CVE-2026-46266, UBUNTU-CVE-2026-46266

## What is CVE-2026-46266?

CVE-2026-46266 is a critical denial of service vulnerability in Linux kernel, published on 3 Jun 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:

inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP

Yizhou Zhao reported that simply having one RAW socket on protocol
IPPROTO_RAW (255) was dangerous.

  socket(AF_INET, SOCK_RAW, 255);

A malicious incoming ICMP packet can set the protocol field to 255
and match this socket, leading to FNHE cache changes.

inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST")
pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner

"man 7 raw" states:

  A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able
  to send any IP protocol that is specified in the passed header.
  Receiving of all IP protocols via IPPROTO_RAW is not possible
  using raw sockets.

Make sure we drop these malicious packets.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-46266?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46266?

Apply the vendor's patch.

## Is CVE-2026-46266 being exploited?

There is no known exploitation of CVE-2026-46266 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-2026-46266 and fix it if it is affected.

What it is: CVE-2026-46266 is a critical denial of service vulnerability in Linux kernel, published on 3 Jun 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-2026-46266 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-2026-46266/ (Markdown: https://insights.sbomify.com/CVE-2026-46266/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46266
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46266
- OSV: https://osv.dev/vulnerability/CVE-2026-46266

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46266/
Summaries are generated and may contain mistakes; the official description above is the record.