# CVE-2025-68471: Avahi has a reachable assertion in lookup_start

> An attacker can crash the Avahi daemon by sending specific unsolicited mDNS announcements, causing a denial of service for local network service discovery.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 12 Jan 2026
- **Updated:** 12 Jan 2026
- **Also known as:** ALPINE-CVE-2025-68471, AZL-74277, AZL-74291, BELL-CVE-2025-68471, DEBIAN-CVE-2025-68471, ECHO-b6a0-85de-738f, GHSA-56rf-42xr-qmmg, MINI-jcj2-wwxf-9243, ROOT-OS-DEBIAN-12-CVE-2025-68471, ROOT-OS-DEBIAN-13-CVE-2025-68471

## What is CVE-2025-68471?

CVE-2025-68471 is a medium-severity denial of service vulnerability in avahi, published on 12 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In 0.9-rc2 and earlier, avahi-daemon can be crashed by sending 2 unsolicited announcements with CNAME resource records 2 seconds apart.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2025-68471?

It affects 1 product.


Products: Avahi Avahi.

## How do I fix CVE-2025-68471?

Upgrade to a fixed version.

## Is CVE-2025-68471 being exploited?

There is no known exploitation of CVE-2025-68471 in the wild and no public exploit code.

## Other vulnerabilities in avahi

- [CVE-2017-6519](https://insights.sbomify.com/CVE-2017-6519/): Denial of service in n/a (critical 9.1)
- [CVE-2021-26720](https://insights.sbomify.com/CVE-2021-26720/): Path traversal in n/a (high 7.8)
- [CVE-2026-24401](https://insights.sbomify.com/CVE-2026-24401/): Avahi has Uncontrolled Recursion in lookup_handle_cname function (medium 6.5)
- [CVE-2025-68468](https://insights.sbomify.com/CVE-2025-68468/): Avahi has a reachable assertion in lookup_multicast_callback (medium 6.5)
- [CVE-2023-38469](https://insights.sbomify.com/CVE-2023-38469/): Reachable assertion in avahi_dns_packet_append_record (medium 6.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68471 and fix it if it is affected.

What it is: CVE-2025-68471 is a medium-severity denial of service vulnerability in avahi, published on 12 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-68471 in the wild and no public exploit code.

Affected product: avahi. 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-2025-68471/ (Markdown: https://insights.sbomify.com/CVE-2025-68471/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68471
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68471
- OSV: https://osv.dev/vulnerability/CVE-2025-68471

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68471/
Summaries are generated and may contain mistakes; the official description above is the record.