eml_parser: Recursion DoS via nested message/rfc822 attachments

published 2026-05-08 6 mo ago modified 2026-07-24 3 mo ago also GHSA-g47v-rwmh-r9f8 , PYSEC-2026-2468 , EUVD-2026-31977

cvss: 6.3; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits: 0; none known

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 3.0.1, EmlParser.get_raw_body_text() recurses unconditionally for every nested message/rfc822 attachment without any depth limit. An attacker who can supply a badly crafted EML file with approximately 120 nested message/rfc822 parts triggers an unhandled RecursionError and aborts parsing of the message. A 12 KB EML file is enough to crash a worker. Though this causes the parser to crash, it is an unlikely scenario as the suggested EML that crashes the parser would not pass basic RFC compliance tests. This vulnerability is fixed in 3.0.1.

Patch / fix

fixed in 1

pypi eml-parser 3.0.1

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-27)

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/GOVCERT-LU/eml_parser/security/advisories/GHSA-g47v-rwmh-r9f8 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.3	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA	4.0	6.3	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem	package	affected	fixed in
pypi	eml-parser	<3.0.1	3.0.1

Affected products

GOVCERT-LU eml_parser

Classification

Weakness

CWE-674 Uncontrolled Recursion

References

github.com /GOVCERT-LU/eml_parser/security/advisories/GHSA-g47v-rwmh-r9f8
exploit, web
nvd.nist.gov /vuln/detail/CVE-2026-44844
advisory
github.com /GOVCERT-LU/eml_parser
package
pypi.org /project/eml-parser
package
github.com /advisories/GHSA-g47v-rwmh-r9f8
advisory

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.

Summary