CVE-2026-47080 — CDATA Section Breakout via Unsanitised ]]> in xml_builder
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Joshnuss Xml Builder).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Joshnuss | Xml Builder | ≥ 0.0.7 and < 2.4.1≥ 26766f884ed19adee1563522c7afb5f056a6f3b5 and < bfb1ada071ccc1e384c30f782197ca5154106706 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 2.1 | CVSS 4.0 | Low | — | — | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db via NIST National Vulnerability Database |
| 2.1 | CVSS 4.0 | Low | — | — | EEF via CVE Program (cve.org) e CISA ADP |
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · joshnuss/xml builder
- SSVC assessment updated
- Record published
- CVSS changed · 2.1
- Source status changed · → Awaiting Analysis
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
5 on the record
Elsewhere on this site
Related CVEs (same products)
- Low CVE-2026-47079 Round-trip Corruption via Improper Entity Escaping in xml_builder Aug 21, 2026
- Low CVE-2026-48590 Element and Attribute Names Injected Verbatim into XML Output in xml_builder Aug 21, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-47080 is "CDATA Section Breakout via Unsanitised ]]> in xml_builder", rated Low. It affects Xml Builder (Joshnuss); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 2.1 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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