# CVE-2026-74724: ipvs: avoid out-of-bounds write in ip_vs_nat_icmp

> A local attacker can trigger an out-of-bounds write in the Linux kernel IPVS module by modifying packets during processing, potentially leading to code execution or privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-97194, BELL-CVE-2026-74724, DEBIAN-CVE-2026-74724, GHSA-qcch-2r2r-xcw2, UBUNTU-CVE-2026-74724

## What is CVE-2026-74724?

CVE-2026-74724 is a high-severity memory corruption vulnerability in Linux, published on 22 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ipvs: avoid out-of-bounds write in ip_vs_nat_icmp

Sashiko warns that local attacker can modify the packet
while it is processed by IPVS. Some places read the
IP ihl field multiple times which can cause out-of-bounds
access. One such place is ip_vs_nat_icmp where we
can write after the validated area.

Fix it by providing ciph argument just like it is done for
IPv6 and use ciph->len as offset to the embedded transport
header.

Modify some IPv4 header checks by reading the ihl field
only once.

## Which versions are affected by CVE-2026-74724?


## How do I fix CVE-2026-74724?

Apply the vendor's patch.

## Is CVE-2026-74724 being exploited?

There is no known exploitation of CVE-2026-74724 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74724 and fix it if it is affected.

What it is: CVE-2026-74724 is a high-severity memory corruption vulnerability in Linux, published on 22 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74724 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-2026-74724/ (Markdown: https://insights.sbomify.com/CVE-2026-74724/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74724
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74724
- OSV: https://osv.dev/vulnerability/CVE-2026-74724

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74724/
Summaries are generated and may contain mistakes; the official description above is the record.