CVE-2026-29780

eml_parser: Path Traversal in Official Example Script Leads to Arbitrary File Write

This vulnerability is limited to the example script only and does not affect the core eml_parser library. However, as the script is part of the official repository and is likely to be adapted for production use, an attacker supplying a crafted email could achieve arbitrary file write within the execution context.

Potential attack scenarios include:

• Cron job injection: filename="../../etc/cron.d/backdoor"
• Web shell upload: filename="../../var/www/html/shell.php"
• SSH key injection: filename="../../home/user/.ssh/authorized_keys"

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-29780 has a CVSS score of 5.5 (Medium). The vector is requires local access, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.0.1); upgrading removes the vulnerable code path.

Kodem intelligence

import os.path

for a in m['attachment']:
    filename = os.path.basename(a['filename'])
    out_filepath = out_path / filename

    if not out_filepath.resolve().is_relative_to(out_path.resolve()):
        print(f'[!] Skipping suspicious filename: {a["filename"]}')
        continue

    print(f'\tWriting attachment: {out_filepath}')
    with out_filepath.open('wb') as a_out:
        a_out.write(base64.b64decode(a['raw']))

1. What is CVE-2026-29780? CVE-2026-29780 is a medium-severity path traversal vulnerability in eml-parser (pip), affecting versions < 2.0.1. It is fixed in 2.0.1. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-29780? CVE-2026-29780 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of eml-parser are affected by CVE-2026-29780? eml-parser (pip) versions < 2.0.1 is affected.
4. Is there a fix for CVE-2026-29780? Yes. CVE-2026-29780 is fixed in 2.0.1. Upgrade to this version or later.
5. Is CVE-2026-29780 exploitable, and should I be worried? Whether CVE-2026-29780 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-29780 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-29780? Upgrade eml-parser to 2.0.1 or later.