CVE-2026-47080 CDATA Section Breakout via Unsanitised ]]> in xml_builder
Attackers can inject arbitrary XML markup by breaking out of CDATA sections in xml_builder, potentially corrupting downstream XML processing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-47080?
CVE-2026-47080 is a low-severity vulnerability in joshnuss xml_builder, published on 21 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
XML Injection vulnerability in joshnuss xml_builder (XmlBuilder module) allows Content Spoofing, XML Injection.
This vulnerability is associated with program files lib/xml_builder.ex and program routines XmlBuilder.generate/1, XmlBuilder.generate/2, XmlBuilder.escape/1.
The escape/1 clause for {:cdata, data} in lib/xml_builder.ex concatenates data verbatim between the CDATA opener <![CDATA[ and closer ]]> without rewriting or splitting on the embedded ]]> sequence. Because CDATA sections have no internal escape mechanism, the only safe way to embed arbitrary bytes is to split on ]]> and emit adjacent CDATA sections. An attacker who can supply input containing ]]> closes the CDATA section early; any bytes that follow are parsed as ordinary XML markup by downstream consumers, allowing injection of arbitrary elements, text, or entity references into the output document.
This issue affects xml_builder: from 0.0.7 before 2.4.1.
Weakness: CWE-91
Which versions are affected by CVE-2026-47080?
1 open source package ship an affected version, including xml_builder.
| Package | Affected | Fixed in |
|---|---|---|
xml_builder Hex | From 0.0.7 | 2.4.1 |
How do I fix CVE-2026-47080?
Upgrade xml_builder to 2.4.1 or later.
Is CVE-2026-47080 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47080 exists.
Sources
Also known as EEF-CVE-2026-47080, GHSA-67r9-hmxw-h595.