Vulnerability · Published Aug 21, 2026 · Assigned by EEF

CVE-2026-48590Element and Attribute Names Injected Verbatim into XML Output 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 86.7% 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.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.

Affected products (as reported)

Vendor	Product	Versions
joshnuss	xml_builder	0.0.1 – before 2.4.1
joshnuss	xml_builder	9fb49131ad3ee146a4c9db9bc175bdffe32e30a0 – before d5c0aec32a8eecbb440fb9bbb0f59d4d188d5859

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

References

https://github.com/joshnuss/xml_builder/security/advisories/GHSA-r82p-3q2p-728w vendor-advisory, related
https://cna.erlef.org/cves/CVE-2026-48590.html related
https://osv.dev/vulnerability/EEF-CVE-2026-48590 related
https://github.com/joshnuss/xml_builder/commit/d5c0aec32a8eecbb440fb9bbb0f59d4d188d5859 patch