CVE-2026-33400
Received Received - Intake
Stored XSS in Wallos Payment Rename Enables Session Hijacking

Publication date: 2026-03-24

Last updated on: 2026-03-26

Assigner: GitHub, Inc.

Description
Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 4.7.0, a stored cross-site scripting (XSS) vulnerability in the payment method rename endpoint allows any authenticated user to inject arbitrary JavaScript that executes when any user visits the Settings, Subscriptions, or Statistics pages. Combined with the wallos_login authentication cookie lacking the HttpOnly flag, this enables full session hijacking. This issue has been patched in version 4.7.0.
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Meta Information
Published
2026-03-24
Last Modified
2026-03-26
Generated
2026-06-16
AI Q&A
2026-03-24
EPSS Evaluated
2026-06-15
NVD
CVE-2026-33400
EUVD
EUVD-2026-14946
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
wallosapp wallos to 4.7.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-79 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.
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Executive Summary

The vulnerability exists in Wallos, an open-source personal subscription tracker, prior to version 4.7.0. It is a stored cross-site scripting (XSS) flaw in the payment method rename endpoint. This allows any authenticated user to inject arbitrary JavaScript code that executes when any user visits certain pages such as Settings, Subscriptions, or Statistics.

Additionally, because the authentication cookie (wallos_login) lacks the HttpOnly flag, the injected JavaScript can hijack user sessions by stealing this cookie.

This vulnerability has been fixed in version 4.7.0.

Impact Analysis

This vulnerability can lead to full session hijacking for users of Wallos. An attacker who is authenticated can inject malicious JavaScript that executes in other users' browsers, potentially stealing their session cookies and gaining unauthorized access to their accounts.

Such unauthorized access could allow attackers to view or manipulate personal subscription data or other sensitive information accessible through the application.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, you should upgrade Wallos to version 4.7.0 or later, where the stored cross-site scripting (XSS) issue in the payment method rename endpoint has been patched.

Additionally, ensure that the wallos_login authentication cookie is set with the HttpOnly flag to prevent session hijacking.

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