---
title: "CVE-2026-61741: http4s-scala-xml has an XML External Entity (XXE) processing issue"
url: https://erroneo.us/security/cve/CVE-2026-61741/
description: "CVE-2026-61741 (org.http4s:http4s-scala-xml_2.12 (Maven)): http4s-scala-xml provides EntityDecoder[F, scala.xml.Elem] instances that parse XML message…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-24
date_modified: 2026-09-29
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-61741"
kev: false
cvss: 9.3
epss: 0.00294
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-61741: http4s-scala-xml has an XML External Entity (XXE) processing issue

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.3% , percentile 21: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 21% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes org.http4s:http4s-scala-xml_2.12 (Maven) <= 0.24.0, fixed in 0.24.1 ; org.http4s:http4s-scala-xml_2.13 (Maven) <= 0.24.0, fixed in 0.24.1 ; org.http4s:http4s-scala-xml_2.13 (Maven) >= 1.0.0-M1, <= 1.0.0-M38.1, fixed in 1.0.0-M39 ; org.http4s:http4s-scala-xml_3 (Maven) <= 0.24.0, fixed in 0.24.1 . Check your lockfile, including transitive dependencies.

## What it is

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

- Maven `org.http4s:http4s-scala-xml_2.12` <= 0.24.0 → fixed: 0.24.1
- Maven `org.http4s:http4s-scala-xml_2.13` <= 0.24.0 → fixed: 0.24.1
- Maven `org.http4s:http4s-scala-xml_2.13` >= 1.0.0-M1, <= 1.0.0-M38.1 → fixed: 1.0.0-M39
- Maven `org.http4s:http4s-scala-xml_3` <= 0.24.0 → fixed: 0.24.1
- Maven `org.http4s:http4s-scala-xml_3` >= 1.0.0-M1, <= 1.0.0-M38.1 → fixed: 1.0.0-M39

## Affected products (CVE record)

- http4s http4s-scala-xml: < 0.24.1, >= 1.0.0-M1, < 1.0.0-M39

## Severity

- GitHub_M CVSS 3.1: 9.3 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L`
- GitHub CVSS 3.1: 9.3 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.29% probability of exploitation activity in the next 30 days; percentile 21.

## Sources

- [GitHub Advisory GHSA-cjx3-73hr-rpw7](https://github.com/advisories/GHSA-cjx3-73hr-rpw7)
- [CVE.org record CVE-2026-61741](https://www.cve.org/CVERecord?id=CVE-2026-61741)
- [NVD entry CVE-2026-61741](https://nvd.nist.gov/vuln/detail/CVE-2026-61741)
- [github.com](https://github.com/http4s/http4s-scala-xml/security/advisories/GHSA-cjx3-73hr-rpw7)
- [github.com](https://github.com/http4s/http4s-scala-xml/commit/326f965a2c45fc2ddbc22545dcf551b0f719f4c8)
- [github.com](https://github.com/http4s/http4s-scala-xml/releases/tag/v0.24.1)
- [github.com](https://github.com/http4s/http4s-scala-xml/releases/tag/v1.0.0-M39)

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Source page: https://erroneo.us/security/cve/CVE-2026-61741/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt