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Medium · 5.3 CVE-2026-55619 EUVD-2026-65703GHSA-m66c-fw79-6359PYSEC-2026-3833

eml_parser: Parser DoS via deeply nested parentheses in e-mail headers

Published Aug 25, 2026 · Updated Aug 25, 2026 · Assigned by GitHub_M

Description

eml_parser serves as a python module for parsing eml files and returning various information found in the e-mail as well as computed information. Prior to 3.0.2, eml_parser.parser.HeaderParser.header_fetch_parse in eml_parser/parser.py uses email.utils.getaddresses() to parse address-bearing e-mail headers. A deeply nested CFWS comment construct exhausts the standard-library recursive descent parser's call stack and raises RecursionError, which is not caught and therefore aborts parsing of the entire message. An attacker can disrupt SOC pipelines that process untrusted EML files, although callers already need to handle exceptions from malformed or pathological messages. This issue is fixed in version 3.0.2.

Affected products

VendorProductAffectedFixed
GOVCERT-LU eml_parser < 3.0.2 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI eml-parser < 3.0.2 3.0.2 GHSA-m66c-fw79-6359

References