CVE-2026-48590 Element and Attribute Names Injected Verbatim into XML Output in xml_builder
Attackers can inject arbitrary XML markup into generated documents via unescaped element and attribute names in the xml_builder library.
- 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-2026-48590?
CVE-2026-48590 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.element/1, XmlBuilder.element/2, XmlBuilder.element/3.
Element names, attribute names, and doctype identifiers are interpolated verbatim into the serialized XML output without validation or escaping of structural characters (<, >, ", ', &). An attacker who can influence a name argument (for example, an element name derived from a JSON object key or an HTTP form field name) can inject arbitrary XML markup including extra elements, comments, and event-handler attributes into the output document.
This issue affects xml_builder: from 0.0.1 before 2.4.1.
Weakness: CWE-91
Which versions are affected by CVE-2026-48590?
1 open source package ship an affected version, including xml_builder.
| Package | Affected | Fixed in |
|---|---|---|
xml_builder Hex | From 0.0.1 | 2.4.1 |
How do I fix CVE-2026-48590?
Upgrade xml_builder to 2.4.1 or later.
Is CVE-2026-48590 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48590 exists.
Sources
Also known as EEF-CVE-2026-48590, GHSA-r82p-3q2p-728w.