# CVE-2026-18726: Open-iscsi: open-iscsi: denial of service in iscsiuio router advertisement parsing

> Remote attackers can cause a denial of service in the iscsiuio daemon by sending crafted ICMPv6 Router Advertisements, leading to infinite loops and high CPU usage.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** AZL-95925, DEBIAN-CVE-2026-18726, GHSA-q9p8-qgxc-hw66, UBUNTU-CVE-2026-18726

## What is CVE-2026-18726?

CVE-2026-18726 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 12 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw was found in open-iscsi. This vulnerability allows a remote attacker on the same local network segment to cause a Denial of Service (DoS) in the iscsiuio daemon. By sending a specially crafted Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement with a zero-length option, the attacker can trigger an infinite loop. This leads to sustained CPU usage, rendering the daemon unresponsive and impacting system availability. A secondary risk of out-of-bounds reads exists with a short IPv6 payload, though no memory corruption or data exposure has been confirmed.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-18726?

It affects 1 product.


Products: Redhat Enterprise Linux.

## How do I fix CVE-2026-18726?

Apply the vendor's patch.

## Is CVE-2026-18726 being exploited?

There is no known exploitation of CVE-2026-18726 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Enterprise Linux

- [CVE-2018-14667](https://insights.sbomify.com/CVE-2018-14667/): Red Hat JBoss RichFaces Framework Expression Language Injection (critical 9.8, exploited in the wild)
- [CVE-2021-20325](https://insights.sbomify.com/CVE-2021-20325/): Missing fixes for CVE-2021-40438 and CVE-2021-26691 in the versions of httpd, as shipped in Red Hat Enterprise Linux 8.5.0, causes a securit (critical 9.8)
- [CVE-2018-25011](https://insights.sbomify.com/CVE-2018-25011/): Memory corruption in libwebp (critical 9.8)
- [CVE-2018-25014](https://insights.sbomify.com/CVE-2018-25014/): Other in libwebp (critical 9.8)
- [CVE-2014-3585](https://insights.sbomify.com/CVE-2014-3585/): Supply chain in redhat-upgrade-tool (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18726 and fix it if it is affected.

What it is: CVE-2026-18726 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 12 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-2026-18726 in the wild and no public exploit code.

Affected product: Redhat Enterprise 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-2026-18726/ (Markdown: https://insights.sbomify.com/CVE-2026-18726/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18726
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18726
- OSV: https://osv.dev/vulnerability/CVE-2026-18726

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18726/
Summaries are generated and may contain mistakes; the official description above is the record.