PYSEC-2026-558
Vulnerability from pysec - Published: 2026-06-29 11:50 - Updated: 2026-06-29 12:05A Path Traversal vulnerability in the partition_msg function allows an attacker to write or overwrite arbitrary files on the filesystem when processing malicious MSG files with attachments.
## Impact
An attacker can craft a malicious .msg file with attachment filenames containing path traversal sequences (e.g.,
../../../etc/cron.d/malicious). When processed with process_attachments=True, the library writes the attachment to an
attacker-controlled path, potentially leading to:
- Arbitrary file overwrite
- Remote code execution (via overwriting configuration files, cron jobs, or Python packages)
- Data corruption
- Denial of service
## Affected Functionality
The vulnerability affects the MSG file partitioning functionality when process_attachments=True is enabled.
## Vulnerability Details The library does not sanitize attachment filenames in MSG files before using them in file write operations, allowing directory traversal sequences to escape the intended output directory.
## Workarounds
Until patched, users can:
- Set process_attachments=False when processing untrusted MSG files
- Avoid processing MSG files from untrusted sources
- Implement additional filename validation before processing
| Name | purl | unstructured |
|---|
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.18.17"
},
"package": {
"ecosystem": "PyPI",
"name": "unstructured"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.18.18"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.0.1.dev0",
"0.10.0",
"0.10.1",
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],
"aliases": [
"CVE-2025-64712",
"GHSA-gm8q-m8mv-jj5m"
],
"details": "A Path Traversal vulnerability in the `partition_msg` function allows an attacker to write or overwrite arbitrary files on the filesystem when processing malicious MSG files with attachments.\n\n ## Impact\n An attacker can craft a malicious .msg file with attachment filenames containing path traversal sequences (e.g.,\n `../../../etc/cron.d/malicious`). When processed with `process_attachments=True`, the library writes the attachment to an\n attacker-controlled path, potentially leading to:\n\n - Arbitrary file overwrite\n - Remote code execution (via overwriting configuration files, cron jobs, or Python packages)\n - Data corruption\n - Denial of service\n\n ## Affected Functionality\n The vulnerability affects the MSG file partitioning functionality when `process_attachments=True` is enabled.\n\n ## Vulnerability Details\n The library does not sanitize attachment filenames in MSG files before using them in file write operations, allowing directory\n traversal sequences to escape the intended output directory.\n\n ## Workarounds\n Until patched, users can:\n - Set `process_attachments=False` when processing untrusted MSG files\n - Avoid processing MSG files from untrusted sources\n - Implement additional filename validation before processing",
"id": "PYSEC-2026-558",
"modified": "2026-06-29T12:05:50.985804Z",
"published": "2026-06-29T11:50:51.107727Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/Unstructured-IO/unstructured/security/advisories/GHSA-gm8q-m8mv-jj5m"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-64712"
},
{
"type": "WEB",
"url": "https://github.com/Unstructured-IO/unstructured/commit/b01d35b2373fd087d2e15162b9c021663c97155d"
},
{
"type": "PACKAGE",
"url": "https://github.com/Unstructured-IO/unstructured"
},
{
"type": "PACKAGE",
"url": "https://pypi.org/project/unstructured"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-gm8q-m8mv-jj5m"
}
],
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Unstructured has Path Traversal via Malicious MSG Attachment that Allows Arbitrary File Write"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.