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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.5 · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS

• CVE-2026-29780: 0.28% estimated exploitation activity in the next 30 days; percentile 20.11 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The official example script examples/recursivelyextractattachments.py contains a path traversal vulnerability that allows arbitrary file write outside the intended output directory. Attachment filenames extracted from parsed emails are directly used to construct output file paths without any sanitization, allowing an attacker-controlled filename to escape the target directory. Details File: examples/recursivelyextractattachments.py Lines: 61–64 The value a['filename'] is attacker-controlled via crafted email attachment headers: No path normalization or boundary validation is performed before writing. PoC 1. Create a malicious .eml file: 2. Run the example script: 3. Expected: ./safe/pwned.txt 4. Actual: ./outside/pwned.txt ← written outside the intended directory Verified on Kali Linux with emlparser installed via pip in a virtual environment. Impact This vulnerability is limited to the example script only and does not affect the core emlparser library. However, as the script…

Published by the source

5 Mar 2026, 00:16 UTC

Last modified by the source

13 Jul 2026, 07:26 UTC

Source last checked

26 Oct 2026, 13:37 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-389r-rccm-h3h5

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-389r-rccm-h3h5

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# Patch Next advisory brief: CVE-2026-29780

Advisory: eml_parser: Path Traversal in Official Example Script Leads to Arbitrary File Write
IDs: CVE-2026-29780, GHSA-389r-rccm-h3h5
Record: https://patchnext.com/advisories/cve-2026-29780 (revision 2, source checked 26 Oct 2026, 13:37 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: eml-parser 2.0.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI eml-parser: affected < 2.0.1; fixed in 2.0.1

## Suggested inspection (read-only)
- `python -m pip show eml-parser`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on eml-parser.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-389r-rccm-h3h5 (OSV record GHSA-389r-rccm-h3h5 lists affected ranges: PyPI eml-parser >=0 <2.0.1 (fixed))
- Verified: https://github.com/advisories/GHSA-389r-rccm-h3h5 (GitHub-reviewed advisory GHSA-389r-rccm-h3h5 lists affected ranges: PyPI eml-parser >=0 <2.0.1)

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