CVE-2026-61741 http4s-scala-xml has an XML External Entity (XXE) processing issue
Attackers can exploit unconfigured XML parsers in http4s-scala-xml to read local files, perform SSRF, or cause denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-61741?
CVE-2026-61741 is a critical vulnerability in http4s-scala-xml, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-611
Which versions are affected by CVE-2026-61741?
10 open source packages ship an affected version, including org.http4s:http4s-scala-xml_2.13, org.http4s:http4s-scala-xml_2.12 and org.http4s:http4s-scala-xml_3.
| Package | Affected | Fixed in |
|---|---|---|
org.http4s:http4s-scala-xml_2.13 Maven | All versions | 0.24.1 |
org.http4s:http4s-scala-xml_2.13 Maven | All versions | 0.24.1 |
org.http4s:http4s-scala-xml_2.13 Maven | From 1.0.0-M1 | 1.0.0-M39 |
org.http4s:http4s-scala-xml_2.13 Maven | From 1.0.0-M1 | 1.0.0-M39 |
org.http4s:http4s-scala-xml_2.12 Maven | All versions | 0.24.1 |
org.http4s:http4s-scala-xml_2.12 Maven | All versions | 0.24.1 |
4 more packages
org.http4s:http4s-scala-xml_3 Maven | All versions | 0.24.1 |
org.http4s:http4s-scala-xml_3 Maven | All versions | 0.24.1 |
org.http4s:http4s-scala-xml_3 Maven | From 1.0.0-M1 | 1.0.0-M39 |
org.http4s:http4s-scala-xml_3 Maven | From 1.0.0-M1 | 1.0.0-M39 |
How do I fix CVE-2026-61741?
Upgrade org.http4s:http4s-scala-xml_2.13 to a fixed version for your release line: 0.24.1 or 1.0.0-M39.
Is CVE-2026-61741 being exploited?
There is no known exploitation of CVE-2026-61741 in the wild and no public exploit code.
Sources
Also known as GHSA-cjx3-73hr-rpw7.