XML External Entity (XXE) Injection Affecting expat package, versions <2.2.6-2


Severity

Recommended
0.0
high
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
7.11% (94th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ECHOLATEST-EXPAT-18426724
  • published30 Jul 2026
  • disclosed24 Jun 2019

Introduced: 24 Jun 2019

CVE-2018-20843  (opens in a new tab)
CWE-611  (opens in a new tab)

How to fix?

Upgrade Echo:latest expat to version 2.2.6-2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream expat package and not the expat package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a high amount of RAM and CPU resources while processing (enough to be usable for denial-of-service attacks).

References

CVSS Base Scores

version 3.1