# CVE-2026-47079

## Summary

- **CVE ID:** CVE-2026-47079
- **Severity:** LOW
- **CVSS Score:** 2.1 (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)
- **CWE:** CWE-838
- **Published:** Aug 21, 2026
- **Last Modified:** Aug 21, 2026

## Description

Inappropriate Encoding for Output Context vulnerability in joshnuss xml_builder (XmlBuilder module) allows Content Spoofing, Cross-site Scripting.

This vulnerability is associated with program files lib/xml_builder.ex and program routines XmlBuilder.generate/1, XmlBuilder.generate/2, XmlBuilder.escape_string/1, XmlBuilder.escape_entity/1.

XmlBuilder.generate/1 does not escape literal & characters in text or attribute values when they are followed by an entity-like token (lt;, gt;, amp;, quot;, apos;). As a result, attacker-supplied input such as &lt;script&gt; is emitted verbatim into the serialized XML rather than being escaped to &amp;lt;script&amp;gt;. When a downstream XML parser later reads the document, it decodes the entity sequences into the literal characters <script>, promoting inert-looking text into real markup. This allows an attacker to bypass upstream filters that block raw < and > characters, injecting markup into any downstream consumer that parses the produced XML and renders the text content in a markup-sensitive context (HTML, SVG, RSS/Atom feeds). Both element text and attribute values are affected.

This issue affects xml_builder: from 0.0.6 before 2.4.1.

## Affected Products

- joshnuss — xml_builder (0.0.6)
- joshnuss — xml_builder (aae31e6e8ac837bcbb8afb816c0d14324b5cfe2b)

## References

- [CNA](https://github.com/joshnuss/xml_builder/security/advisories/GHSA-5hjx-8g53-cmvm)
- [CNA](https://cna.erlef.org/cves/CVE-2026-47079.html)
- [CNA](https://osv.dev/vulnerability/EEF-CVE-2026-47079)
- [CNA](https://github.com/joshnuss/xml_builder/commit/c3390e2046ec297b3bb8c30d5779cdfd6508c275)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.14%
- **EPSS Percentile:** 3.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-12._