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Fencer Vulns
medium 5.3

CVE-2026-55619 json

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

published 2026-08-25 2 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-65703 , GHSA-m66c-fw79-6359 , PYSEC-2026-3833

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi eml-parser 3.0.2
  • govcert.lu eml_parser 3.0.2

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-55619 updated cvss 7.5

eml_parser: eml_parser: Denial of Service vulnerability in email header parsing

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
OSV 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
pypi eml-parser
<3.0.2
3.0.2

Affected products

  • GOVCERT-LU eml_parser

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling
  • CWE-1124 Excessively Deep Nesting

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.