VulnerabilityPublished 7 May 2026

Netbox-data-flows Has Stored XSS

Affects netbox-data-flowsSource GCVE Database

CVSS 8.7 High : upgrade to 1.5.1 soon.

Data as of 27 Oct 2026, 00:07 UTC

CVSS 3.1 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 1.5.1

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Changed
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

What to do

Upgrade netbox-data-flows to 1.5.1.

Affected software

Product	Affected	Fixed in
PyPInetbox-data-flows	Affected <1.5.1	Fixed in 1.5.1

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Description

### Summary 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.py` - `ObjectAlias.name` is user-controlled (`CharField`) - `ObjectAlias.__str__()` returns `self.name` directly - `netbox_data_flows/tables/dataflows.py` - `DataFlowTable.sources` and `DataFlowTable.destinations` use `ObjectAliasListColumn` - `netbox_data_flows/tables/columns.py` - `ObjectAliasListColumn.render()` calls `object_list_to_string(value.all(), linkify=True)` - `netbox_data_flows/utils/helpers.py` - `object_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

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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What to do

Affected software

Description

WeaknessesCWE-79

Technical details

References

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