CVE-2026-26266
Received Received - Intake
Stored XSS in AliasVault Web Client Email Rendering

Publication date: 2026-03-03

Last updated on: 2026-03-05

Assigner: GitHub, Inc.

Description
AliasVault is a privacy-first password manager with built-in email aliasing. A stored cross-site scripting (XSS) vulnerability was identified in the email rendering feature of AliasVault Web Client versions 0.25.3 and lower. When viewing received emails on an alias, the HTML content is rendered in an iframe using srcdoc, which does not provide origin isolation. An attacker can send a crafted email containing malicious JavaScript to any AliasVault email alias. When the victim views the email in the web client, the script executes in the same origin as the application. No sanitization or sandboxing was applied to email HTML content before rendering. This vulnerability is fixed in 0.26.0.[
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Meta Information
Published
2026-03-03
Last Modified
2026-03-05
Generated
2026-06-16
AI Q&A
2026-03-04
EPSS Evaluated
2026-06-15
NVD
CVE-2026-26266
EUVD
EUVD-2026-9332
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
aliasvault aliasvault to 0.26.0 (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 is a stored cross-site scripting (XSS) issue in the AliasVault Web Client versions 0.25.3 and lower. It occurs in the email rendering feature where received emails on an alias are displayed. The HTML content of these emails is rendered inside an iframe using the srcdoc attribute, which does not provide origin isolation.

Because there is no sanitization or sandboxing of the email HTML content before rendering, an attacker can send a specially crafted email containing malicious JavaScript to any AliasVault email alias. When the victim views this email in the web client, the malicious script executes with the same origin as the application, potentially compromising the user's session or data.

This vulnerability is fixed in version 0.26.0 of AliasVault.

Impact Analysis

This vulnerability can have severe impacts because it allows an attacker to execute malicious JavaScript in the context of the AliasVault web application.

  • An attacker could steal sensitive information such as passwords or session tokens.
  • The attacker could perform actions on behalf of the victim within the application.
  • It could lead to a complete compromise of the user's account or data confidentiality.

The CVSS v3.1 base score of 9.3 indicates a critical severity with high impact on confidentiality and integrity.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, you should upgrade AliasVault Web Client to version 0.26.0 or later, where the issue has been fixed.

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