CVE-2026-18311

Deferred Deferred - Pending Action

Stored XSS in Readwise Reader for Android

Publication date: 2026-09-25

Last updated on: 2026-09-28

Assigner: CERT/CC

Description

Readwise Reader for Android contains a cross-site scripting vulnerability due to missing HTML sanitization in its processing of imported document metadata. Attacker-controlled fields such as the author meta tag are inserted into a WebView via innerHTML, enabling stored XSS that executes on synced devices when the malicious document is opened.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-25

Last Modified

2026-09-28

Generated

2026-10-16

AI Q&A

2026-09-25

EPSS Evaluated

2026-10-14

NVD

CVE-2026-18311

EUVD

EUVD-2026-87232

Affected Vendors & Products

Vendor	Product	Version / Range
readwise	reader	-

Helpful Resources

Exploitability

CWE

KEV

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.

Attack-Flow Graph

Executive Summary

This is a stored cross-site scripting (XSS) vulnerability in Readwise Reader for Android. It occurs because the app does not properly sanitize HTML in imported document metadata, such as author or title fields. Attackers can inject malicious JavaScript into these fields, which gets stored and later executed in the app's WebView when the document is opened on synced devices.

Detection Guidance

Detecting this vulnerability requires checking the installed version of Readwise Reader for Android. Compare your version against 8.10.1 or later. If using an older version, the app is vulnerable. No specific commands are provided in the resources, but inspecting app metadata or update logs can help verify the version.

Impact Analysis

An attacker could steal sensitive data like stored documents, login credentials, or session tokens. The malicious script runs within the app's WebView, potentially allowing unauthorized access to your account or personal information. This risk increases if you import documents from untrusted sources.

Compliance Impact

This vulnerability could lead to unauthorized data access or exfiltration, violating GDPR's data protection principles or HIPAA's security requirements for protected health information. Organizations may face compliance penalties if user data is compromised due to insufficient safeguards.

Mitigation Strategies

Update Readwise Reader for Android to version 8.10.1 or later immediately. Avoid importing or syncing documents from untrusted sources to reduce exposure. Monitor for suspicious activity in your account or synced data.

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