CVE-2026-44844 eml_parser: Recursion DoS via nested message/rfc822 attachments
Attackers can crash the eml_parser library by supplying deeply nested EML files, causing a denial of service in applications using the parser.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44844?
CVE-2026-44844 is a medium-severity denial of service vulnerability in GOVCERT-LU eml_parser, published on 26 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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 3.0.1, 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.
Weakness: CWE-674
Which versions are affected by CVE-2026-44844?
3 open source packages ship an affected version, including eml_parser and eml-parser.
| Package | Affected | Fixed in |
|---|---|---|
eml_parser PyPI | All versions | 3.0.1 |
eml-parser PyPI | All versions | 3.0.1 |
eml-parser PyPI | All versions | 3.0.1 |
How do I fix CVE-2026-44844?
Upgrade eml_parser to 3.0.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-44844 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44844 exists.
Sources
Also known as GHSA-g47v-rwmh-r9f8, PYSEC-2026-2468.