Vulnerability · Published Aug 21, 2026 · Assigned by EEF

CVE-2026-47080CDATA Section Breakout via Unsanitised ]]> in xml_builder

Low 2.1

In plain English

A low-severity security flaw in xml_builder from joshnuss. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities).

Severity (CVSS 4.0)2.1Low

Exploit odds (30 days)0.2%top 87.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
joshnuss	xml_builder	0.0.7 – before 2.4.1
joshnuss	xml_builder	26766f884ed19adee1563522c7afb5f056a6f3b5 – before bfb1ada071ccc1e384c30f782197ca5154106706

Weakness: CWE-91 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N

In plain English

Official description

Affected products (as reported)

References