Excessively Deep Nesting Affecting eml-parser package, versions [,3.0.2)


Severity

Recommended
0.0
high
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.63% (48th 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-PYTHON-EMLPARSER-20158945
  • published27 Sept 2026
  • disclosed25 Aug 2026
  • creditUnknown

Introduced: 25 Aug 2026

CVE-2026-55620  (opens in a new tab)
CWE-1124  (opens in a new tab)
CWE-770  (opens in a new tab)

How to fix?

Upgrade eml-parser to version 3.0.2 or higher.

Overview

eml-parser is a Python EML parser library

Affected versions of this package are vulnerable to Excessively Deep Nesting through the processing of deeply nested parentheses in Received headers. An attacker can cause excessive CPU consumption by submitting specially crafted EML files with a large number of nested parentheses, leading to significant delays in email processing pipelines.

CVSS Base Scores

version 4.0
version 3.1