CVE-2026-47180

What it is

Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.5, DNSIncoming._decode_labels_at_offset recurses once per DNS-name compression pointer, and a single mDNS packet carrying chained pointers can trigger a RecursionError that escapes DNSIncoming.__init__, causing sustained CPU burn, log flooding, and degraded mDNS-dependent features for unauthenticated hosts on the local link over UDP/5353 (224.0.0.251 / ff02::fb). This issue is fixed in version 0.149.5.

At a glance

Exploitability

Can be exploited from the same network segment without logging in. High risk of service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-17 19:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-17 19:48 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 6.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-07-17 19:17 UTC

Last modified

2026-08-17 19:48 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-674

Record status

Analyzed

Affected

• Paulsm Zeroconf < 0.149.5

Attack profile CVSS 3.1 · 6.5

Attack vector

Adjacent network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-47180.md and follow it. Check whether this project is affected by CVE-2026-47180. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge