# CVE-2026-74669: ipvs: clear IPv4 options after rebasing tunnel ICMP errors

> A stack out-of-bounds write in the Linux kernel IPVS module allows attackers to potentially execute code or cause a denial of service via crafted ICMP errors.

- **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:** 22 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-97091, BELL-CVE-2026-74669, DEBIAN-CVE-2026-74669, GHSA-8jr6-vjx9-8g96, UBUNTU-CVE-2026-74669

## What is CVE-2026-74669?

CVE-2026-74669 is a critical memory corruption vulnerability in Linux, published on 22 Aug 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:

ipvs: clear IPv4 options after rebasing tunnel ICMP errors

ip_vs_in_icmp() rebases an skb from the outer ICMP packet to the
quoted original request before passing it to icmp_send(). However,
IPCB(skb)->opt still describes the outer IPv4 header.

A timestamp option in the outer header can therefore leave an offset
that points into the quoted transport header after the rebase.
__ip_options_echo() treats a byte at that stale location as the option
length and copies it into the fixed-size option storage on the
__icmp_send() stack, causing a stack out-of-bounds write.

Clear the stale option metadata after resetting the network header.
Keep the remaining control block fields, including the ingress
interface used by the ICMP response path.

## Which versions are affected by CVE-2026-74669?


## How do I fix CVE-2026-74669?

Apply the vendor's patch.

## Is CVE-2026-74669 being exploited?

There is no known exploitation of CVE-2026-74669 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74669 and fix it if it is affected.

What it is: CVE-2026-74669 is a critical memory corruption vulnerability in Linux, published on 22 Aug 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-2026-74669 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-2026-74669/ (Markdown: https://insights.sbomify.com/CVE-2026-74669/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74669
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74669
- OSV: https://osv.dev/vulnerability/CVE-2026-74669

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74669/
Summaries are generated and may contain mistakes; the official description above is the record.