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Grav Admin Plugin is vulnerable to Cross-Site Scripting (XSS) Stored endpoint `/admin/accounts/groups/[group]` parameter `data[readableName]`

Moderate severity GitHub Reviewed Published Dec 1, 2025 in getgrav/grav • Updated Dec 2, 2025

Package

composer getgrav/grav (Composer)

Affected versions

< 1.8.0-beta.27

Patched versions

1.8.0-beta.27

Description

Summary

A Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/accounts/groups/Grupo endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[readableName] parameter. The injected scripts are stored on the server and executed automatically whenever the affected page is accessed by users, posing a significant security risk.


Details

Vulnerable Endpoint: POST /admin/accounts/groups/Grupo
Parameter: data[readableName]

The application fails to properly validate and sanitize user input in the data[readableName] parameter. This lack of input handling allows attackers to inject arbitrary script content that is stored in the application and executed in the browser of any user who views the affected group configuration.


PoC

Payload:

<ScRipT>alert('PoC-XSS')</ScRipT>

  1. Navigate to Accounts > Groups in the administrative panel.

  2. Create a new group or edit an existing one.

  3. In the Display Name field (data[readableName]), insert the payload above and save the changes.

image

The following HTTP request was generated during this action:
image

  1. Next, go to Accounts > Users and open any user profile.

image

  1. The malicious script is executed immediately in the browser when the page loads, confirming the existence of a Stored XSS vulnerability.

image


Impact

Stored XSS vulnerabilities can result in serious consequences, including:

  • Session hijacking: Attackers can steal authentication cookies or tokens

  • Malware delivery: Inserting scripts that download malicious content

  • Credential theft: Capturing usernames and passwords through injected forms

  • Sensitive data exposure: Accessing data stored in the browser or the application

  • Browser takeover: Executing arbitrary commands in the user’s session

  • Phishing attacks: Redirecting users to fake login or malicious sites

  • Website defacement: Altering page content shown to users

  • Reputational damage: Undermining trust in the platform or organization

by CVE-Hunters

References

@rhukster rhukster published to getgrav/grav Dec 1, 2025
Published by the National Vulnerability Database Dec 1, 2025
Published to the GitHub Advisory Database Dec 2, 2025
Reviewed Dec 2, 2025
Last updated Dec 2, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required High
User interaction Active
Vulnerable System Impact Metrics
Confidentiality Low
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality High
Integrity High
Availability High

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:L/VI:L/VA:N/SC:H/SI:H/SA:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(7th percentile)

Weaknesses

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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. Learn more on MITRE.

CVE ID

CVE-2025-66312

GHSA ID

GHSA-rmw5-f87r-w988

Source code

Credits

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