GHSA-V7QW-HX66-4W9X
Vulnerability from github – Published: 2026-05-07 22:31 – Updated: 2026-05-07 22:31Summary
An authenticated user who can create or edit ObjectAlias objects can store arbitrary HTML/JavaScript in an alias name. That payload is later rendered unescaped in DataFlow table views, causing a stored XSS when another user views the affected page.
Details
The issue is caused by unsafe HTML generation in the plugin’s custom table column renderer.
Relevant code on main (bf96eac, same commit as origin/main at the time of review):
netbox_data_flows/models/objectaliases.pyObjectAlias.nameis user-controlled (CharField)ObjectAlias.__str__()returnsself.namedirectlynetbox_data_flows/tables/dataflows.pyDataFlowTable.sourcesandDataFlowTable.destinationsuseObjectAliasListColumnnetbox_data_flows/tables/columns.pyObjectAliasListColumn.render()callsobject_list_to_string(value.all(), linkify=True)netbox_data_flows/utils/helpers.pyobject_list_to_string()builds raw anchor tags with:python mark_safe(separator.join(f'<a href="{o.get_absolute_url()}">{o}</a>' for o in objects))
The alias text ({o}) is inserted into HTML without escaping, then the whole string is marked safe. Because ObjectAlias.__str__() returns the user-supplied name, HTML/JS in the alias name is executed in the victim’s browser.
This affects any page rendering DataFlowTable, including at least:
- the main Data Flow list page
- model tabs that reuse DataFlowTable
PoC
Environment:
- NetBox with netbox-data-flows installed
- No special plugin configuration required
Steps:
1. Log in as a user with permission to create or edit ObjectAlias and DataFlow.
2. Create a new ObjectAlias with the following name:
html
<img src=x onerror=alert(document.domain)>
3. Create or edit a DataFlow so this alias is present in either sources or destinations.
4. Log in as another user and open the Data Flow list page in the plugin UI.
5. The JavaScript executes when the table renders the alias list.
A simple path to trigger is the Data Flow list page. Any other page that renders DataFlowTable should also be tested.
Impact
This is a stored cross-site scripting vulnerability.
Impacted users:
- any authenticated user who can view a page rendering the affected DataFlow table
- especially higher-privileged NetBox users, because an attacker with lower privileges may target them by planting a malicious alias name
Possible impact: - session theft - execution of privileged actions in the victim’s session - exfiltration of data visible to the victim in NetBox
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.5.0"
},
"package": {
"ecosystem": "PyPI",
"name": "netbox-data-flows"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.5.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-07T22:31:32Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\nAn authenticated user who can create or edit `ObjectAlias` objects can store arbitrary HTML/JavaScript in an alias name. That payload is later rendered unescaped in `DataFlow` table views, causing a stored XSS when another user views the affected page.\n\n### Details\nThe issue is caused by unsafe HTML generation in the plugin\u2019s custom table column renderer.\n\nRelevant code on `main` (`bf96eac`, same commit as `origin/main` at the time of review):\n\n- `netbox_data_flows/models/objectaliases.py`\n - `ObjectAlias.name` is user-controlled (`CharField`)\n - `ObjectAlias.__str__()` returns `self.name` directly\n- `netbox_data_flows/tables/dataflows.py`\n - `DataFlowTable.sources` and `DataFlowTable.destinations` use `ObjectAliasListColumn`\n- `netbox_data_flows/tables/columns.py`\n - `ObjectAliasListColumn.render()` calls `object_list_to_string(value.all(), linkify=True)`\n- `netbox_data_flows/utils/helpers.py`\n - `object_list_to_string()` builds raw anchor tags with:\n ```python\n mark_safe(separator.join(f\u0027\u003ca href=\"{o.get_absolute_url()}\"\u003e{o}\u003c/a\u003e\u0027 for o in objects))\n ```\n\nThe alias text (`{o}`) is inserted into HTML without escaping, then the whole string is marked safe. Because `ObjectAlias.__str__()` returns the user-supplied name, HTML/JS in the alias name is executed in the victim\u2019s browser.\n\nThis affects any page rendering `DataFlowTable`, including at least:\n- the main Data Flow list page\n- model tabs that reuse `DataFlowTable`\n\n### PoC\nEnvironment:\n- NetBox with `netbox-data-flows` installed\n- No special plugin configuration required\n\nSteps:\n1. Log in as a user with permission to create or edit `ObjectAlias` and `DataFlow`.\n2. Create a new `ObjectAlias` with the following name:\n ```html\n \u003cimg src=x onerror=alert(document.domain)\u003e\n ```\n3. Create or edit a `DataFlow` so this alias is present in either `sources` or `destinations`.\n4. Log in as another user and open the Data Flow list page in the plugin UI.\n5. The JavaScript executes when the table renders the alias list.\n\nA simple path to trigger is the Data Flow list page. Any other page that renders `DataFlowTable` should also be tested.\n\n### Impact\nThis is a stored cross-site scripting vulnerability.\n\nImpacted users:\n- any authenticated user who can view a page rendering the affected `DataFlow` table\n- especially higher-privileged NetBox users, because an attacker with lower privileges may target them by planting a malicious alias name\n\nPossible impact:\n- session theft\n- execution of privileged actions in the victim\u2019s session\n- exfiltration of data visible to the victim in NetBox",
"id": "GHSA-v7qw-hx66-4w9x",
"modified": "2026-05-07T22:31:32Z",
"published": "2026-05-07T22:31:32Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/Alef-Burzmali/netbox-data-flows/security/advisories/GHSA-v7qw-hx66-4w9x"
},
{
"type": "PACKAGE",
"url": "https://github.com/Alef-Burzmali/netbox-data-flows"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "netbox-data-flows has stored XSS in ObjectAlias names rendered inside DataFlow tables"
}
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.