Vulnerability · Published Sep 24, 2026 · Assigned by GitHub_M
CVE-2026-61741http4s-scala-xml has an XML External Entity (XXE) processing issue
Critical 9.3
In plain English
A critical-severity XML external entity in http4s-scala-xml from http4s. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
http4s-scala-xml provides `EntityDecoder[F, scala.xml.Elem]` instances that parse XML message bodies. Prior to versions 0.24.1 and 1.0.0-M39, these decoders used a `javax.xml.parsers.SAXParserFactory` obtained from `SAXParserFactory.newInstance` without any security configuration. With the JDK's default settings, the parser resolves DOCTYPE declarations, external general and parameter entities, and external DTDs.An application that uses these decoders to parse untrusted XML is vulnerable to XML External Entity (XXE) attacks. An attacker can craft a request that discloses local files readable by the service process, performs server-side request forgery (SSRF) against internal network resources, and/or causes denial of service through entity expansion. Versions 0.24.1 and 1.0.0-M39 fix the issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.http4s:http4s-scala-xml_2.12 | 0.24.1 | GHSA-cjx3-73hr-rpw7 |
| Maven | org.http4s:http4s-scala-xml_2.13 | 0.24.1 | GHSA-cjx3-73hr-rpw7 |
| Maven | org.http4s:http4s-scala-xml_2.13 | 1.0.0-M39 | GHSA-cjx3-73hr-rpw7 |
| Maven | org.http4s:http4s-scala-xml_3 | 0.24.1 | GHSA-cjx3-73hr-rpw7 |
| Maven | org.http4s:http4s-scala-xml_3 | 1.0.0-M39 | GHSA-cjx3-73hr-rpw7 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| http4s | http4s-scala-xml | < 0.24.1>= 1.0.0-M1, < 1.0.0-M39 |
Weakness: CWE-611 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L